High-Speed C# .NET Excel Spreadsheet API Library

Quick Start - Generating XLSX from Scratch

Document Solutions for Excel, .NET allows developers to create a new Excel workbook programmatically from within a .NET Core application. By utilizing the Workbook class, users can add worksheets, assign values to cells, and save the file in XLSX format. This simple process is perfect for generating dynamic reports, data exports, or initial templates directly from .NET applications. The example process includes creating a new console or MVC app, adding necessary NuGet packages, and using basic code to define the workbook’s structure, resulting in an automated workflow that produces Excel files without manual intervention.

• View Demo and Code
• Getting Started Documentation

Open & Save Workbook

The Open and Save Workbook features offer a powerful solution for opening and saving workbooks in multiple formats, such as .xlsm, .xltx, .csv, .html, .pdf, .json, .ssjson, and .sjs within your .NET applications. With the Open method, users can load entire workbooks, choosing from various options such as skipping unnecessary recalculations or excluding unused styles, ensuring fast and efficient file handling.

The Save method provides full control over workbook export, enabling users to preserve data integrity, apply password protection, and manage file formats and layout structure. This flexibility is ideal for projects requiring regular data manipulation, offering precise control over how workbooks are opened, modified, and saved, ensuring optimal performance and security.

• View Demo and Code
• Open and Save Workbook Documentation

Custom Data-Bound Excel Reports

Document Solutions for Excel, .NET allows users to create fully customizable Excel reports that are dynamically linked to data sources. By integrating live data with the Excel report templates through the AddDataSource and ProcessTemplate methods, this feature enables the generation of real-time, tailored reports that reflect up-to-date information.

Users can define specific data ranges, apply filters, and utilize advanced formatting options to create polished, professional reports that match organizational requirements. This functionality is perfect for creating interactive, data-driven reports where the content updates automatically based on data changes, making it an essential tool for those looking to automate and streamline their reporting processes within a .NET application.

• View Demo and Code
• Templates Documentation
• Learn More About Generating Excel Reports

Worksheet Management

The Worksheet Management features provide comprehensive tools for managing worksheets in a workbook. Users can easily add new worksheets, delete or copy existing ones, and move them within the workbook or between workbooks. The feature also allows for advanced actions like protecting worksheets with or without passwords, and activating specific sheets for focused operations. Additionally, the ability to organize worksheets by naming and indexing helps in efficiently managing large datasets. This feature streamlines the process of modifying and securing worksheets, making it an essential tool for data manipulation and reporting in .NET applications.

• View Demo and Code
• Working with Worksheets Documentation

Data Binding

Document Solutions for Excel, .NET allows seamless integration of live data into Excel workbooks by binding external data sources to worksheets, cells, or tables through the built-in DataSource property. You can bind JSON strings, DataTables, or custom objects directly to a sheet or specific cells, automatically or manually linking the data fields to their respective columns. With options for binding paths and auto-generation of columns, this feature supports a variety of scenarios from simple data binding to complex, real-time reporting. Additionally, it provides the ability to bind tables and automatically adjust the table size to accommodate data source changes, making it an essential tool for building dynamic, data-driven Excel reports in .NET applications.

• View Demo and Code
• Data Binding Documentation

Form Controls

The Form Controls features enable the addition of interactive elements like buttons, checkboxes, dropdowns, option buttons, and other controls to Excel worksheets. These controls allow users to interact with data by selecting options, entering values, or triggering actions. The feature supports creating forms like feedback or consent forms and enables dynamic control over linked cells, providing real-time data updates. Users can also customize control properties, including visibility, placement, and locking to ensure appropriate user interaction. Additionally, these controls can be exported in various formats, with the ability to exclude them from export if desired, making them versatile for both interactive and static reports.

• View Demo and Code
• Form Controls Documentation

Themes & Colors

The Themes and Colors features allow users to apply both built-in and custom themes to Excel workbooks, affecting elements like font styles, color schemes, and chart titles. Users can easily set a workbook's theme using predefined options found in the Themes class, such as the Berlin theme, or create personalized themes with custom color schemes and fonts tailored to specific needs. The feature also supports fine-grained control over cell colors, borders, and tabs using theme colors, standard colors, or custom colors defined by RGB, RGBA, or hexadecimal values. This flexibility ensures that workbooks are not only functional but also visually engaging and aligned with branding or design standards.

• View Demo and Code
• Themes and Colors Documentation

File Operations

Document Solutions for Excel, .NET provides extensive functionality for handling various file types within your .NET applications. Users can import and export Excel files in multiple formats, including .xlsx, .xlsm, .csv, .json, .pdf, and .sjs. You can also manage specific sheets, data ranges, or the entire workbook when saving or opening files. The export feature supports converting workbooks to formats like PDF, HTML, and image files, ensuring flexibility in delivering reports and data. Additionally, the import and export functions offer custom parsing options for CSV and JSON formats, enhancing compatibility with external data systems. This makes it ideal for businesses looking to integrate and automate diverse file handling processes within their .NET-based solutions.

• View Demo and Code
• File Operations Documentation

Import/Export XLSX

The .NET Excel API, Document Solutions for Excel, provides a comprehensive solution for importing and exporting Excel XLSX files using C# in .NET applications with flexibility and efficiency.

The Open method allows users to load spreadsheets with options such as skipping formula recalculations, excluding unused styles, and preserving digital signatures. The Save method supports exporting workbooks with advanced controls, including formula exclusion, compact mode saving, and password protection.

For scenarios where only data is needed, the ImportData method enables selective import from specific worksheets, tables, or cell ranges, improving performance when handling large datasets. The library also includes XlsxOpenOptions and XlsxSaveOptions classes, providing fine-tuned control over import flags and export preferences, such as ignoring empty regions, preserving binding sources, and including auto-merged cells.

• Import Excel File Demo and Code
• Export Excel File Demo and Code
• Import and Export .xlsx Document Documentation

Import/Export CSV

Server-side Excel APIs provide a powerful solution for importing and exporting CSV files with full control over data formatting, delimiters, and parsing rules. Using CsvOpenOptions and CsvSaveOptions, you can customize how CSV data is handled, including setting column, row, and cell separators to match different file structures. The library also allows precise control over numeric and date conversions, ensuring that data is interpreted correctly based on your needs.

For advanced scenarios, Document Solutions for Excel supports custom parsing through the ICsvParser interface, giving you the ability to define unique rules for handling text, numbers, and formulas during import. This is especially useful when working with CSV files that contain mixed data types or require non-standard formatting.

Additionally, CSV exports can be configured to include selective quoting, trimmed blank spaces, and specific encoding options to ensure compatibility across different applications. Whether you're working with simple tabular data or complex datasets, this .NET Excel library provides the flexibility needed to streamline your CSV workflows.

• View Demo and Code
• Import and Export CSV File Documentation

Import/Export JSON Stream

Document Solutions for Excel allows seamless import and export of JSON streams for workbooks and worksheets, making it easy to work with SpreadJS. You can convert a workbook to JSON using the ToJson method and import JSON back into a workbook using the FromJson method. This supports handling formulas, external references, and large workbooks with complex data.

For worksheets, the ToJson and FromJson methods allow exporting and importing JSON for individual sheets. This enables efficient data transfer, including displaying large Excel files in SpreadJS. JSON streams can be used to update worksheets in the same or another workbook, though importing to a different workbook may result in data conflicts or loss of SpreadJS-specific styles.

DsExcel also provides error handling when importing JSON files. The FromJson method returns a list of errors, including formula errors detected by the FormulaJsonError class and data validation issues reported by DataValidationJsonError. This helps identify and resolve issues when loading JSON into an Excel workbook.

• View Demo and Code
• Import and Export JSON Documentation

Export to PDF

This C# .NET Excel library lets developers export workbooks, worksheets, or specific ranges to PDF using the Save() method. Each worksheet becomes a new page, and only the active sheet can be exported separately. Images are optimized to reduce file size while maintaining quality.

The PdfSaveOptions class provides customization, including security settings, metadata, and replacing Excel form controls with PDF fields. You can add JavaScript with OpenActionScript, adjust image quality, and control pagination.

Additional options allow exporting shapes, charts, slicers, Pivot Tables, form controls, and more while preserving the spreadsheet layout.

• View Demo and Code
• Export to PDF Documentation

Export to HTML

Using a .NET Excel API developers can easily export Excel workbooks, worksheets, or specific ranges to HTML for easy web publishing. The HTMLSaveOptions class allows options like exporting images as Base64, preserving gridlines and headings, and choosing between internal, inline, or external CSS, users have complete control over the output. HTML export settings also support scalable widths, tooltips, and document properties, making it ideal for sharing data online.

• View Demo and Code
• Export to HTML Documentation

Import Data

This .NET Excel API supports importing data from various sources like arrays, collections, data tables, and custom objects using the ImportData method.

This allows users to efficiently populate spreadsheets while preserving formatting and structure. Through the DataImportOptions, users can set options like InsufficientSpaceHandling, IncludeColumnHeader, and ColumnsSelector help control data import behavior, ensuring flexibility and ease of use.

• View Demo and Code
• Import Data Documentation

Import DataTable

Document Solutions for Excel allows developers to import a DataTable into an Excel worksheet using the ImportData method. This makes it easy to transfer structured data, such as financial records or reports, into a spreadsheet. You can define column types, populate rows, and apply basic formatting to ensure a clean and readable layout.

Once imported, the data automatically adjusts to fit the worksheet, preserving structure and accuracy. Additional styling options like headers and number formatting can be applied for a polished presentation. This approach simplifies data integration and enhances Excel-based reporting.

• View Demo and Code
• Import Table Data Documentation

Import Portions of Data from Existing Files

Programmatically import portions of data from an existing Excel .xlsx files using C# and a .NET Excel API’s ImportData method. This method enables users to fetch data from a specific worksheet, table, or cell range without loading unnecessary elements like formatting, formulas, or styles. It optimizes performance, especially when working with large Excel files. The GetNames method can be used to retrieve available source names within a file.

• View Demo and Code
• Import Data Only Documentation

Convert to Image

Document Solutions for Excel supports exporting worksheets, specific cell ranges, and various shapes (charts, pictures, slicers, and autoshapes) as images using C# and the API’s ToImage method. Supported formats include PNG, JPG, SVG, and GIF, making it easy to integrate Excel data into Word, PDFs, or presentations.

The ImageSaveOptions class provides customization options such as scaling, background color, gridline visibility, and resolution adjustments. This feature helps users generate high-quality images of spreadsheet content for reports and documentation.

• View Demo and Code
• Covert to Image Documentation

Import/Export Macros .xlsm

Document Solutions for Excel’s .NET Excel library supports importing and exporting Excel macro-enabled workbooks (.xlsm), ensuring that macros, form controls, and ActiveX controls are preserved.

While macros are retained during file operations, the API does not execute them. Users can load, modify, and save .xlsm files without losing macro functionality.

Various import/export options are available through XlsmOpenOptions and XlsmSaveOptions. This feature allows seamless handling of automation scripts while maintaining compatibility with Excel's macro-enabled workflows.

• View Demo and Code
• Import and Export Macros Documentation

Import/Export to SpreadJS Files .sjs

Document Solutions for Excel’s .NET API supports seamless import and export of SpreadJS files, including .sjs, .ssjson, and JSON formats.

The SpreadJS .sjs file format improves performance by handling large and complex spreadsheets efficiently. Users can open and save .sjs files just like .xlsx and configure options such as including styles, formulas, or unused names.

The API also provides methods to convert .sjs files to JSON and back, enabling smooth data interchange. Whether working with SpreadJS-specific features or exporting to Excel, this ensures full compatibility and efficiency.

• View Demo and Code
• Import and Export SpreadJS Files Documentation

Import/Export Excel Templates .xltx

The .NET Excel API allows seamless import and export of Excel template files (.xltx), enabling users to work with pre-designed spreadsheets that include predefined layouts, formatting, and formulas. Instead of manually recreating spreadsheet structures, templates can be loaded, modified, and saved back with minimal effort.

The API provides dedicated options for handling .xltx files, ensuring a smooth workflow. Whether opening templates from a file or a stream, the process is efficient and fully supported.

• View Demo and Code
• Import and Export Excel Templates Documentation

Convert Excel Templates .xltx to PDF

Developers can easily convert Excel template files (.xltx) to PDF in .NET server-side apps, ensuring that form controls such as checkboxes, dropdowns, list boxes, and option buttons are preserved as interactive PDF form fields. By setting the FormFields property in PdfSaveOptions, Excel form controls are mapped to their respective PDF equivalents, allowing users to interact with the exported document.

For cases where button controls should be visible in the final PDF, enabling the PrintObject property ensures their inclusion. However, some Excel-specific controls like group boxes and spinners are not supported in the PDF format. This feature streamlines the transition from Excel templates to fillable PDFs, making it ideal for report generation, surveys, and data collection.

• View Demo and Code
• Export Form Controls to Form Fields Documentation

Create & Delete Charts

The Create and Delete Charts feature allows users to generate and remove charts within Excel workbooks. Using the AddChart method, charts can be inserted at specified positions or directly linked to data ranges, enabling dynamic visual representations of data. This feature supports various chart types, including column, line, and pie charts, with the ability to adjust the size and location of the chart. Users can also bind chart data to specific ranges, ensuring accurate data visualization. Additionally, charts can be deleted with the Delete method, providing seamless management of visual content within worksheets. This functionality is ideal for automating and customizing data presentations in .NET applications.

• View Demo and Code
• Create and Delete Charts Documentation

Column & Bar Charts

Document Solutions for Excel, .NET allows users to add both column and bar charts to Excel worksheets for visually representing data comparisons. Column charts, ideal for tracking changes over time, are perfect for categories along the horizontal axis. Similarly, bar charts, typically used for comparing different categories with horizontal bars, offer several types such as clustered, stacked, and 3D options. With the ability to adjust chart titles, data ranges, and chart styles, users can easily customize visual presentations of data to match reporting needs. Whether for sales analysis, performance tracking, or statistical reporting, this feature enables dynamic chart creation directly within .NET applications.

• Column Chart Demo and Code
• Column Chart Documentation
• Bar Chart Demo and Code
• Bar Chart Documentation

Line & Area Charts

Document Solutions for Excel, .NET enables users to create line and area charts for visualizing trends and changes over time. Line charts display data as connected points along a continuous axis, ideal for showing patterns or trends in time-series data. Area charts enhance line charts by filling the space beneath the lines, providing an emphasis on the magnitude of data trends. Both chart types support customization of data ranges, chart styles, and colors, giving users full control over their visual presentation. These chart options are essential for tracking performance, analyzing trends, and presenting time-based data effectively in .NET applications.

• Line Chart Demo and Code
• Line Chart Documentation
• Area Chart Demo and Code
• Area Chart Documentation

Pie & Donut Charts

Document Solutions for Excel, .NET allows users to create visually appealing pie and donut charts for displaying data as parts of a whole. Pie charts provide a straightforward way to illustrate data distribution by dividing a circle into slices, while donut charts offer a more modern variant with a hollow center, perfect for emphasizing key data points. Both chart types support full customization, including slice colors, data labels, and chart styles, providing flexibility in design and presentation. These charts are ideal for showing percentage distributions, making them an excellent choice for visualizing survey results, budget breakdowns, or market share analysis within .NET applications.

• Pie Chart Demo and Code
• Doughnut Chart Demo and Code
• Pie Chart Documentation

Scatter & Bubble Charts

Document Solutions for Excel, .NET enables the use of scatter and bubble charts for users to visualize the relationships between two or more sets of data. Scatter charts plot individual data points on an X and Y axis, ideal for showing correlations or distributions. Bubble charts extend scatter charts by adding a third dimension, where the size of each data point's bubble represents an additional data value. Both chart types allow for full customization, including axis scaling, bubble sizes, colors, and data labels, making them perfect for complex data analysis. These chart types are ideal for applications such as statistical analysis, financial modeling, or performance comparison within .NET applications.

• Scatter Chart Demo and Code
• Bubble Chart Demo and Code
• XY (Scatter) Chart Documentation

Combo Charts

The Combo Charts feature allows users to combine multiple chart types into a single visualization, such as mixing column and line charts, to represent different data series on the same axis. This is particularly useful for comparing different metrics that have varying scales or units. Users can customize each data series with different chart types, colors, and formatting options to enhance clarity and insight. Combo charts are ideal for reporting scenarios where multiple data trends need to be presented together, such as sales performance against targets, revenue growth alongside cost data, or other comparative data points in .NET applications.

• View Demo and Code
• Combo Chart Documentation

Waterfall Charts

The Waterfall Charts feature enables users to create visualizations that show how sequentially introduced positive or negative values impact an initial value, helping to track data flow and changes over time. These charts are particularly useful in financial analysis to illustrate the impact of various factors like revenue, expenses, and profit. Waterfall charts display the starting value, followed by intermediate increases or decreases, and conclude with a final result, providing a clear view of how values build on or subtract from each other. The feature supports customization of colors, labels, and data points to make the chart more informative and visually appealing within .NET applications.

• View Demo and Code
• Waterfall Chart Documentation

Specialized Charts

Document Solutions for Excel, .NET allows users to create a range of unique, specialized chart types designed to represent complex data in visually engaging and insightful ways. These charts include radar charts for comparing multiple variables, surface charts for 3D data visualizations, and treemap charts for hierarchical data representation. Each specialized chart type offers customization options to adjust styles, colors, and data labels, providing flexibility in how the data is presented. These charts are perfect for specialized analysis, such as comparing performance metrics, visualizing multi-dimensional data, or exploring large data sets in an intuitive way within .NET applications.

• Treemap Chart Demo and Code
• Specialized Chart Documentation

Pivot Charts

Document Solutions for Excel, .NET allows users to generate interactive pivot charts based on pivot table data, enabling dynamic data visualization. Pivot charts are perfect for summarizing and analyzing large datasets, offering various chart types such as column, bar, and line to represent aggregated data. As users interact with the pivot table—such as filtering or rearranging fields—the pivot chart automatically updates to reflect the changes, providing an intuitive way to explore trends, compare categories, and identify patterns in real-time. This feature enhances reporting by integrating the power of pivot tables with the visual clarity of charts in .NET applications.

• View Demo and Code
• Pivot Chart Documentation

Sparklines

The Sparklines feature allows users to insert small, cell-based charts directly into Excel worksheets, offering a visual representation of trends, comparisons, or data fluctuations within a single cell. Sparklines are ideal for condensing large amounts of data into concise visual summaries, making them perfect for dashboards, reports, or performance overviews. Users can customize sparkline types, such as line, column, or win/loss, and apply formatting options like colors or markers to highlight significant data points. This feature is particularly useful in providing quick insights and enhancing the readability of large datasets within .NET applications.

• View Demo and Code
• Sparkline Documentation 

Shapes & Pictures

Document Solutions for Excel, .NET allows users to insert and customize various shapes (such as rectangles, circles, lines, and arrows) and images (including logos and photos) directly into Excel worksheets. These graphical elements can be resized, repositioned, and formatted with options like color, borders, and shadow effects. Additionally, users can align and group shapes, apply rotation, or link images to data for interactive reporting. This feature is ideal for creating visually compelling workbooks, adding annotations, or branding reports within .NET applications, enhancing both the functionality and aesthetics of Excel documents.

• Shape Demo and Code
• Pictures Demo and Code
• Shapes and Pictures Documentation

Conditional Formatting

Document Solutions for Excel, .NET enables users to automatically apply conditional formatting rules to Excel cells based on their values. This includes a wide range of options like color scales, data bars, icon sets, and custom formulas, which visually highlight trends, patterns, or anomalies in the data. By using conditional formatting, users can create more intuitive, data-driven workbooks where specific values or ranges are easily identified through visual cues such as color changes or symbols. This feature is particularly useful for financial analysis, performance tracking, and creating visually compelling reports in .NET applications.

• View Demo and Code
• Conditional Formatting Documentation

Table Slicers

The Table Slicers feature allows users to insert slicers into Excel tables, providing an intuitive, visual way to filter data. Slicers are dynamic controls that allow users to interactively filter data based on specific table columns, such as categories or time periods. By adding slicers via the ISlicer and ISlicerCache interfaces, users can instantly narrow down data displayed in a table, making it easier to explore subsets of information. This feature supports multiple slicers for enhanced control and customization, ensuring a seamless and interactive data analysis experience within .NET applications. Slicers can be easily styled and positioned for improved usability in reports and dashboards.

• View Demo and Code
• Table Slicers Documentation

Pivot Tables

The Pivot Tables feature allows users to create powerful data summaries and perform complex analyses in Excel. Pivot tables automatically organize and categorize data, enabling users to compute totals, averages, and other aggregate functions. With the ability to drag and drop fields, users can easily customize pivot table layouts, filter data, and adjust summary functions for deeper insights. Pivot tables provide a dynamic and flexible way to explore large datasets, making them ideal for tasks such as financial analysis, sales tracking, or performance reporting in .NET applications. The feature also supports customizing table styles for enhanced presentation and readability.

• View Demo and Code
• Pivot Table Documentation

Pivot Slicers

The Pivot Slicers feature allows users to add slicers to pivot tables, providing a visual and interactive way to filter data. Slicers allow users to quickly select and view specific data subsets within the pivot table, making it easier to focus on particular categories, time periods, or metrics. This feature supports multiple slicers for enhanced data control, and slicers can be easily linked to one or more pivot tables to update the data dynamically. Users can customize slicer placement, appearance, and functionality, making it a powerful tool for interactive reporting and data exploration in .NET applications.

• View Demo and Code
• Add Slicer in Pivot Table Documentation

Grouping & Subtotaling

The Grouping and Subtotaling features allow users to organize and summarize large datasets by grouping rows or columns in Excel. This feature enables users to create custom views, making complex spreadsheets easier to navigate. Groups can be expanded or collapsed, allowing for a dynamic view of data. Additionally, users can apply summary rows or subtotals to calculate and display totals for grouped data. This functionality is ideal for simplifying the analysis of large datasets, such as sales data or financial reports, and offers flexibility in structuring and visualizing data in .NET applications.

• View Demo and Code
• Group Documentation

Advanced Sorting

The Advanced Sorting features provided by Document Solutions for Excel, .NET allow users to sort data in Excel based on multiple criteria, including values, colors, font styles, and icons. This flexible sorting system supports complex scenarios such as sorting by values in multiple columns, custom sorting, or organizing data based on color patterns, font colors, or conditional format icons. Users can sort data in both ascending and descending orders, with support for merged cells and various sorting orientations. This feature is ideal for handling complex datasets in .NET applications, enabling more detailed and customized data organization for improved analysis and reporting.

• View Demo and Code
• Sorting Documentation

Custom Filters

The Custom Filters feature allows users to apply advanced filtering techniques to Excel data, enabling them to focus on specific subsets of information. Through the AutoFilter method, users can filter data by numbers, text, date ranges, or even by cell color and icons. This feature supports multi-select filters, dynamic date filters, and various operators, making it easy to refine datasets based on custom criteria. With the ability to filter by color or icon, users can quickly highlight key data points or trends, improving the analysis and presentation of data in .NET applications.

• View Demo and Code
• Filter Documentation

What-If Analysis (Goal Seek, Scenario Manager)

The What-If Analysis feature in Excel allows users to evaluate different scenarios by adjusting values in cells and observing the resulting outcomes without creating multiple sheets. Using Goal Seek, users can specify a desired result and let Excel calculate the necessary input values that would produce that result. Scenario Manager, on the other hand, enables users to define and manage sets of input values to determine potential outcomes based on those values. These tools are invaluable for financial forecasting, budgeting, and optimization tasks, making them powerful for dynamic data analysis in .NET applications.

• View Demo and Code
• What-If Analysis Documentation

Error Checking & Tracing Precedents/Dependents

The Error Checking and Tracing Precedents/Dependents features help users identify and trace relationships between cells in Excel, improving formula management and error detection. By using the GetPrecedents and GetDependents methods, users can highlight the cells that contribute to or depend on specific formulas. This functionality makes it easier to visualize data dependencies, detect errors, and optimize complex formulas. The ability to trace direct and indirect precedents and dependents is particularly useful for understanding large workbooks and ensuring accurate calculations in .NET applications.

• View Demo and Code
• Precedents and Dependents Documentation

Cross-Sheet References & Linking

The Cross-Sheet References and Linking features allow users to create formulas that reference data from external workbooks, both via file paths or web URLs through the GetExcelLinkSources method. This feature enables seamless integration of data across multiple workbooks, allowing users to calculate values and update links between them. Whether using a local file path or a web-based resource, users can employ dynamic linking to ensure their data stays up-to-date. The ability to update link caches and work with external tables makes this feature ideal for complex data analysis tasks, particularly in collaborative and multi-workbook environments within .NET applications.

• View Demo and Code
• Cross Workbook Formula Documentation

Formulas (450+ Excel Functions)

Document Solutions for Excel’s .NET API offers extensive formula support, providing over 450+ built-in Excel functions for advanced data analysis and automation. Users can perform statistical calculations with functions like AVERAGE, MEDIAN, and MODE, apply logical operations using IF, SWITCH, and CHOOSE, and retrieve data efficiently with powerful lookup functions such as VLOOKUP, XLOOKUP, INDEX, and XMATCH. The LET function allows users to assign names to calculation results within a formula, improving readability and performance.

Formulas follow Excel’s operator precedence rules and can be applied to ranges, tables, and dynamic arrays. Additional capabilities include iterative calculations, cross-workbook formulas, and localized formula support, making this .NET API a comprehensive solution for complex server-side Excel computations.

• View Demo and Code
• Formulas Documentation

Create Custom Functions

The .NET Excel library, Document Solutions for Excel, enables users to define and register custom functions, allowing for specialized calculations beyond standard Excel formulas. These functions can be optimized for performance, support nested logic, and interact with web services, making them ideal for enterprise-level spreadsheet applications. Custom functions resemble native Excel functions and can be used across all major Excel platforms, ensuring compatibility and ease of use.

With custom caching control, users can optimize repeated calculations, while volatile functions ensure real-time recalculations when needed. This flexibility allows for advanced implementations, such as conditional summations, complex text operations, error detection, and mathematical computations like greatest common divisors. By registering these functions with the AddCustomFunction method, developers can extend this server-side API’s functionality to handle unique business logic, automate Excel reports, and enhance spreadsheet workflows.

• View Demo and Code
• Custom Functions Documentation

Set Dynamic Array Formulas

The Set Dynamic Array Formulas feature enables users to apply array formulas in Excel, which can process multiple calculations simultaneously across a range of cells. Dynamic arrays automatically "spill" results into adjacent cells, making it easier to perform tasks such as summing values based on criteria, counting occurrences, or computing totals. By using the FormulaArray property of the IRange interface in .NET applications, users can set complex array formulas, simplifying tasks like summing every nth value or calculating values within specified boundaries. This feature is ideal for data-intensive analysis, enabling quick and dynamic results with minimal effort.

• View Demo and Code
• Dynamic Array Formulas Documentation

Iterative Calculation

The Iterative Calculation feature allows users to perform calculations in Excel where a formula is repeatedly recalculated until certain criteria are satisfied. By enabling iterative calculation using the EnableIterativeCalculation property, users can define parameters such as the maximum number of iterations and the maximum allowable difference between formula results. This is useful for solving complex formulas that require iterative refinement, such as calculating loan amortizations or complex financial models. This feature can be easily customized for a variety of calculation scenarios within .NET applications, ensuring that Excel worksheets are dynamically calculated to converge on an accurate result.

• View Demo and Code
• Iterative Calculation Documentation 

Extract PDF Table Data

The Formula Parse and Parse Format Options features allow users to parse and manipulate Excel formulas at the semantic model level using a syntax tree. By leveraging the FormulaSyntaxTree class, users can create, modify, and visit formulas with ease. The Parse method generates a syntax tree from a formula, and the ToString method converts it back to a formula string. This functionality supports parsing formulas in both A1 and R1C1 reference styles, with options to customize the base row and column for each formula. It's ideal for users who need to manipulate complex formulas programmatically in .NET applications, offering flexibility for tasks like replacing function arguments or converting between reference styles.

• View Demo and Code
• Formula Parser Documentation

Formula Tracing

Formula Tracing enables users to identify and track the relationships between cells and formulas in an Excel worksheet. Using methods like GetPrecedents and GetDependents, users can visualize how data flows within a sheet, whether a cell's value is influencing others (precedents) or being affected by them (dependents). This functionality is invaluable for troubleshooting errors, optimizing complex calculations, and ensuring accurate formulas. Users can trace both direct and indirect dependencies, providing deeper insights into how modifications to one cell can impact the rest of the workbook, making it essential for working with large and intricate data models in .NET applications.

• View Demo and Code
• Precedents and Dependents Documentation

Cross Workbook Formula

The Cross Workbook Formula feature enables users to create formulas in one Excel workbook that reference and perform calculations on data from external workbooks. By using folder or web paths, users can link data between workbooks, ensuring up-to-date calculations. With methods such as GetExcelLinkSources and UpdateExcelLinks, users can manage links and refresh the linked data as needed. This functionality supports a variety of scenarios, including summing data across workbooks, and is ideal for consolidating information from multiple sources in .NET applications. The cross-workbook formula approach simplifies workflows and enhances collaboration by dynamically linking workbooks, making it particularly useful for financial reports, project tracking, and other multi-source data tasks.

• View Demo and Code
• Cross Workbook Formula Documentation

Localized Formulas

The Localized Formulas feature allows users to set and retrieve formulas that are automatically localized based on the culture or regional settings of the Excel workbook. By using the FormulaLocal  and FormulaR1C1Local properties, users can ensure that formulas, such as functions, adjust to the corresponding localized names in languages like Japanese and Chinese. This is particularly useful for creating Excel sheets that will be used in different cultural settings, enabling seamless compatibility with local Excel environments. The feature simplifies the process of working with international users, making it ideal for global businesses and applications within .NET environments.

• View Demo and Code
• Localized Formulas Documentation

Defined Names

Defined names enhance .NET formula readability by assigning meaningful names to tables, cell ranges, formulas, and constants. Instead of using direct cell references, defined names allow for a more intuitive approach, especially in financial models, reports, and large datasets.

You can define names at both the workbook and worksheet levels using the Name property in IWorkbook and IWorksheet, and the Name property in ITable. Workbook-level names apply across all sheets, while worksheet-level names are local to a specific sheet. These names appear in Excel’s Name Manager and can be used within formulas for calculations like SUM, COUNT, and constants such as Pi or Euler’s number.

Our .NET Excel API ensures seamless integration of defined names, making spreadsheet formulas more understandable and efficient.

• View Demo and Code
• Defined Names Documentation

Set Table Formula

The Set Table Formula feature allows users to define and apply structured references within Excel tables, enabling more flexible and dynamic calculations. By using table and column names, along with special item specifiers such as #Data, #Totals, or @, users can create formulas that interact directly with specific sections of the table. This eliminates the need for traditional cell references, making formulas more readable and easier to maintain. The feature supports a range of operators like the range, union, and intersection operators, enhancing the flexibility of formulas. Ideal for working with tabular data, this functionality is valuable for automating calculations in .NET applications while keeping the workbook structured and easily updatable.

• View Demo and Code
• Set Table Formula Documentation

Pivot Table Formulas

Pivot Table Formulas enable users to apply different functions, like SUM, AVERAGE, or custom formulas, to pivot table fields for more dynamic data analysis. Users can modify pivot field functions and manage settings such as grand total visibility and row axis layout. The library supports the flexible layout of pivot tables, including compact, outline, and tabular views, and allows for detailed customization like auto-fitting column width and renaming fields for clarity. This feature empowers .NET applications to provide robust and user-friendly pivot table analysis in Excel with advanced formatting options.

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• Apply Different Calculations on Pivot Fields Documentation

Asynchronous Functions

The Asynchronous Functions feature allows users to run custom Excel functions asynchronously, improving performance by allowing multiple tasks to execute concurrently. With the AsyncCustomFunction class and the EvaluateAsync method, developers can create custom functions that return results asynchronously, ideal for scenarios requiring heavy or time-consuming calculations. This feature supports asynchronous image functions, like the IMAGE formula, to load images from URLs, and includes a WaitForCalculationToFinish method to ensure all calculations are completed before proceeding. This is particularly useful for large-scale data processing in .NET applications where non-blocking, parallel computation can significantly reduce processing time.

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• Asynchronous Functions Documentation

Linked Picture

The Linked Picture feature allows users to add dynamic, real-time images in Excel that are linked to a specific range of cells. As values in the referenced range change, the linked picture updates automatically, providing a live view of the data. Using the AddCameraPicture method, users can insert linked pictures at specified positions or within particular cell ranges. The feature supports resizing and formatting the picture just like any other image in Excel. Additionally, users can control transparency settings for the picture and even convert linked pictures to static images. This functionality is especially useful in reporting scenarios where visual updates are needed without manual intervention.

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• Linked Picture Documentation

Ignore Errors in Excel

The Ignore Errors feature enables users to suppress error indicators, such as the green triangle in the top-left corner of a cell, which typically appears when Excel detects an issue like invalid formulas or inconsistent data. By using the IgnoredError property within the IRange interface, developers can specify which types of errors to ignore, including formula discrepancies, text-formatted numbers, empty cell references, and more. This functionality helps maintain cleaner and more visually appealing workbooks, especially when working with large datasets or complex formulas, making it ideal for automated .NET applications where error handling needs to be streamlined and unobtrusive.

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• Ignore Errors in Cell Range Documentation

Excel Calculation Mode

The Excel Calculation Mode feature allows users to control how Excel handles formula calculations in a workbook. Users can select from three calculation modes: Automatic (where Excel recalculates everything on changes), Semiautomatic (calculates everything except data tables and Python formulas), and Manual (calculates only when explicitly triggered by the user, such as by pressing F9). This flexibility is useful for managing large workbooks or ensuring fast export processes without recalculating formulas. The mode setting is managed through the CalculationMode property within the IFormulaOptions interface, optimizing workflow and performance in .NET applications when working with large datasets or complex calculations.

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• Calculation Mode Documentation

Cell Types

Document Solutions for Excel’s .NET API library supports interactive cell types, including Button, CheckBox, ComboBox, Radio List, and Hyperlink, allowing you to enhance user interactions within a spreadsheet. These cell types define both the content and behavior of a cell, making it easier to implement custom functionality.

Users can apply cell types to individual cells, ranges, rows, columns, or entire worksheets. While Excel does not support these features natively, they are fully compatible with SpreadJS and are retained when using JSON I/O.

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• Cell Types Documentation

Range Template Cell

Range Template Cells allow developers to define a structured cell range as a reusable template, simplifying the display of identical data layouts across a worksheet.

This feature eliminates the need to reconfigure styles for multiple ranges and supports dynamic data binding. Once applied, the template functions as a single cell, enabling consistent formatting and improved data visualization. While useful for report generation and structured data representation, note that Excel does not support this feature, meaning it will be lost when saving to an .xlsx file, but can be viewed on the client-side using SpreadJS.

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• Range Template Cell Type Documentation

Data Validation

The Excel API library, Document Solutions for Excel, enables users to programmatically enforce data validation rules in .NET server-side Excel workbooks, ensuring only correct and properly formatted data is entered.

Set constraints for whole numbers, decimals, dates, times, and text length, or create custom rules and dropdown lists for predefined inputs. Configure input prompts and error alerts to guide users and prevent invalid entries. Easily modify, highlight, or remove validation rules as needed to maintain data integrity across worksheets.

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• Data Validation Documentation

Set Styles for Cells

Programmatically apply extensive styling options to a range of cells in a worksheet using C#, including setting fill styles (solid, pattern, or gradient), customizing fonts, and or adjusting borders for better presentation.

Users can apply number formatting for currency, dates, and percentages, as well as fine-tune alignment settings such as horizontal and vertical positioning.

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• Set Sheet Styling Documentation

Merge Cells

The .NET Excel API allows merging multiple cells into a single cell using the Merge method. When merging, only the top-left cell’s content remains, while other data in the range is lost. If all merged cells are empty, the formatting from the top-left cell is applied to the merged area. Users can merge entire ranges or restrict merging to rows within a range, providing flexibility in structuring data presentation.

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• Merge Cells Documentation

Auto Merge Cells

Document Solutions for Excel allows automatic merging of adjacent cells containing identical text using the AutoMerge method. This feature applies when exporting a workbook to formats like PDF, HTML, Image, XLSX, or JSON, ensuring structured data presentation without modifying the workbook itself.

Users can control the merge direction (row, column, or both) and define merge rules for precise formatting. The auto-merge functionality helps streamline reports, tables, and structured data exports while maintaining the integrity of the original spreadsheet.

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• Auto Merge Cells Documentation

Protect Cell Range

The .NET Excel API allows software developers to programmatically protect specific cell ranges by locking them or hiding formulas to prevent unauthorized modifications.

The Locked property of IRange and IStyle ensures that cells remain un-editable when the worksheet is protected. The FormulaHidden property hides formulas from view while still allowing calculations. Users can lock individual cells, apply protection across entire worksheets using styles, or selectively hide formulas. These properties take effect when the worksheet is protected, ensuring secure handling of sensitive data.

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• Protect Cell Range Documentation

Hyperlinks

Developers can create hyperlinks in Excel worksheets, enabling quick access to external files, web pages, email addresses, or other worksheet ranges. Hyperlinks are managed through the Hyperlinks collection within the IWorksheet or IRange interface.

Using the Add method, hyperlinks can be inserted into individual cells or ranges. Users can further configure hyperlinks by setting display text, tooltips, and email subjects. Hyperlinks can also be removed using the Delete method, either from specific cells or the entire worksheet.

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• Hyperlinks Documentation

Barcodes

Document Solutions for Excel provides functionality to insert barcodes in worksheets, making it easy to encode and scan data with precision. Supported barcode types include QR Code, EAN-13, Code128, Data Matrix, PDF417, and more.

Since Excel does not support barcode formulas, barcodes can be generated using functions and later converted into images using the ConvertBarcodeToPicture method. This method allows saving barcodes in various image formats such as SVG (default) or JPG. Additionally, barcode data can be imported and exported using SpreadJS JSON I/O, and barcodes can be embedded into PDF exports for document sharing and printing.

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• Barcodes Documentation

Rich Text in Cells

Our C# .NET Excel library supports rich text formatting, allowing users to apply multiple styles within a single cell. This feature is useful for emphasizing important information, such as company names, product titles, or key figures.

Rich text formatting enables customization of font styles, sizes, colors, and effects like bold, italic, underline, strikethrough, subscript, and superscript. Developers can manipulate rich text using APIs like IRichText, IRange.Characters(), and ITextRun, providing precise control over text formatting. Whether highlighting specific words, inserting formatted text dynamically, or adjusting styles across multiple runs, this feature enhances readability and data presentation in spreadsheets.

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• Rich Text Documentation

Excel Templates

Document Solutions for Excel’s NET API library supports Excel template generation for building structured, repeatable reports that can be populated with dynamic data at runtime. Templates provide a powerful way to streamline report creation while reducing manual errors. Developers can design pre-formatted Excel files and bind them to structured data sources using the API’s Workbook Open and ProcesTemplate methods.

Templates support flexible field expressions like {{ds.FieldName}}, horizontal/vertical expansions, and formula fields for calculating summaries such as totals or averages. 

Once processed, the final workbook can be saved using the Worbkook’s Save method — making it easy to export the filled report to Excel or PDF formats.

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• Template Documentation

Comments

.NET Excel APIs allows you to annotate spreadsheets by adding comments to cells, making it easier to provide explanations, instructions, or contextual notes.

Comments can be customized with different layouts, font styles, and colors. They can be shown or hidden, moved, resized, or deleted as needed. You can also set an author for each comment and use rich text formatting to enhance readability.

The API provides full control over comment management, helping users streamline data presentation while keeping spreadsheets organized.

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• Comments Documentation

Find & Replace Data

Document Solutions for Excel simplifies searching for specific values, formulas, and formatted data within large worksheets. The Find method allows locating occurrences within a specified range, while the Replace method updates values efficiently. Users can perform case-sensitive searches, match entire words, and search within formulas, comments, or text.

The .NET Excel API also supports advanced replacements, such as updating all occurrences of a formula across a sheet. These capabilities streamline data management and improve accuracy when working with extensive spreadsheets.

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• Find and Replace Data Documentation

Digital Signatures

This .NET Excel API enables users to apply digital signatures to Excel workbooks using C#, verifying the integrity and authenticity of documents. Signature lines can be inserted into worksheets, allowing users to add official digital signatures. Additionally, non-visible signatures can be embedded, appearing only in the Excel signature panel.

Signed documents can be validated using certificates, and the API allows for countersigning to preserve existing signatures after modifications. Users can also remove digital signatures while retaining the original signature lines.

The API ensures compatibility with Microsoft Office digital signatures, making it a reliable solution for secure document handling in .xlsx and .xlsm formats.

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• Digital Signature Documentation

Print

Print entire workbooks or individual worksheets using C# and the PrintOut method from the IWorkbook and IWorksheet interfaces. This method accepts a PrintOutOptions object, which lets you configure settings like printer name, number of copies, duplex printing, and page ranges. Printing functionality relies on the PDF engine, requiring the DS.Documents.Imaging.Windows reference.

The PrintOut method is only supported on Windows environments. For other platforms, export the spreadsheet to a PDF before printing.

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• Print Documentation

Enable Logging

This .NET Excel API provides built-in logging support to help diagnose and troubleshoot issues by capturing detailed log records. Logging is disabled by default but can be enabled using Workbook.LoggerFactory allowing logs to be printed to the console or saved to a file. Developers can configure logging levels such as debug, info, warning, and error, ensuring only relevant logs are captured. The logging system is based on Microsoft.Extensions.Logging and supports logging for JSON and Excel I/O operations, as well as PDF exports.

Users can also enable thread ID logging for detailed process analysis. To configure logging, a JSON configuration file is required, specifying log levels and file paths.

• Logging Documentation

Generate Paginated Spreadsheet Reports

.NET Excel API’s enable the creation of paginated spreadsheet reports, ideal for structured documents such as invoices, medical reports, and product catalogs. Reports can be paginated by page size, generating a new sheet when content exceeds the set dimensions, or by record count per page, ensuring a fixed number of records per worksheet grouped by a specific field.

When pagination mode is enabled, the .NET Excel API dynamically generates page worksheets labeled with their index, such as “Sheet1_Page1” and “Sheet1_Page2.” This mode overrides page breaks and allows shapes and images to repeat based on layout rules.

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• Pagination Properties and Functions Documentation

Client-Side Data File Viewer

Document Solutions Data Viewer is a JavaScript-based client-side viewer for loading and previewing XLSX, CSV, Apache Arrow, Parquet, and SpreadJS (SSJSON and .sjs) files. Designed for modern web applications, it supports all major browsers and integrates with JavaScript frameworks. The viewer provides essential features like zooming, scrolling, advanced search, and clipboard support, along with the ability to display tables, sparklines, hidden sheets, hyperlinks, and conditional formatting for better data readability.

DsDataViewer offers two licensing options: the Standard Viewer License, included with Document Solutions for Excel .NET or Java, supports core viewing features, while the Professional Viewer License adds sorting, filtering, slicers, and visualization support for charts, shapes, and barcodes.

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• Document Solutions Data Viewer Documentation

Support for SpreadJS Features

Document Solutions for Excel supports JSON, .ssjson, and .sjs I/O of the popular SpreadJS JavaScript spreadsheet files. You can import, modify, and export files created with SpreadJS. This allows you to programmatically create spreadsheets files on the server using Document Solutions for Excel, send them up to the client to edit using the Excel-like spreadsheet SpreadJS UI then send any changes back down to the server for any further processing, creating a comprehensive spreadsheet viewing and editing solution for both the server and client needs.

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• Supported SpreadJS Features Documentation