RadzenSpreadsheet: a Free and Open-Source Blazor Spreadsheet

Let's be honest - Excel is everywhere whether we like it or not (and will probably outlive all of us). Sooner or later, almost every business app needs spreadsheet integration - somewhere users can enter formulas, sort and filter, chart their numbers, and move data in and out of Excel.

Radzen.Blazor now includes a dedicated component for all that: RadzenSpreadsheet - a complete spreadsheet with a formula engine, Excel import and export, and charts you can drop straight into a sheet. All written in C# and running in the browser. It's free, MIT-licensed, and available now as of June 24, 2026.

Try the live spreadsheet demos →

Here's a look at what it does.

What sets it apartlinkLink to this section

A spreadsheet that calculates, charts, and round-trips Excel - and that you can bend to fit your app - is hard to build from scratch. A few things we are especially proud of:

• Your own Blazor components in a cell. Render and edit a spreadsheet cell with any Blazor component: a rating, a status badge, a progress bar, a date picker, a thumbnail. The cell looks and behaves exactly as your app needs, inside a spreadsheet that calculates around it.
• Charts inside the sheet. Insert a chart that lives in the grid beside its data, drawn by the RadzenChart engine.
• Precise control over what users can do. Switch editing, sorting, filtering, charts, conditional formatting - any capability - on or off independently, or intercept any action before it runs and veto it from your own code. Build a locked-down, app-specific spreadsheet.

What it doeslinkLink to this section

Embed RadzenSpreadsheet in your app and your users get a tool they already know how to use:

• Write formulas across multiple sheets - =SUM(B1:B12), =VLOOKUP(...), nested logic - and watch every dependent cell recalculate live as they type.
• Format cells with fonts, colors, borders, number and date formats, alignment, text wrapping, and merged cells.
• Apply conditional formatting and data validation to keep data clean and readable.
• Sort and filter, build styled tables, and freeze panes so headers stay put while users scroll.
• Drop charts straight into the sheet, right next to the data they describe.
• Insert images and hyperlinks, autofill series, copy and paste ranges, and undo or redo anything.
• Open an Excel file, edit it in the browser, and export it back to .xlsx or .csv - formatting, multiple sheets, and frozen panes all come through intact.

New to Radzen Blazor?linkLink to this section

Radzen Blazor is an open-source library of 145+ free, MIT-licensed UI components (as of June 2026) for C# and .NET - grids, charts, forms, scheduling. RadzenSpreadsheet is its biggest addition yet.

A formula engine with 100+ Excel functionslinkLink to this section

At the core is a formula engine we built from scratch in C# - lexer, parser, evaluator, and a dependency graph that recalculates only what changed and catches circular references.

It comes with 100+ familiar Excel functions:

• Aggregation and logic: SUM, SUMIF, SUMIFS, COUNT, COUNTIF, COUNTIFS, AVERAGE, AVERAGEIF, SUBTOTAL, AGGREGATE, IF, IFS, IFERROR, SWITCH, AND, OR, NOT.
• Lookup and reference: VLOOKUP, HLOOKUP, XLOOKUP, INDEX, MATCH, XMATCH, CHOOSE.
• Text: CONCAT, TEXTJOIN, LEFT, RIGHT, MID, FIND, SEARCH, SUBSTITUTE, REPLACE, TRIM, UPPER, LOWER, PROPER, TEXT, VALUE.
• Date and time: TODAY, NOW, DATE, YEAR, MONTH, DAY, WEEKDAY, WEEKNUM, EDATE, EOMONTH, DATEDIF, NETWORKDAYS, WORKDAY.
• Math and statistics: ROUND, ROUNDUP, ROUNDDOWN, INT, TRUNC, ABS, MOD, POWER, SQRT, PRODUCT, SUMPRODUCT, MEDIAN, LARGE, SMALL, STDEV, VAR, RANK.

You can also register your own functions in C# and call them from a formula like any built-in.

Excel in code - no UI requiredlinkLink to this section

The spreadsheet engine is also available as a document processing API you can use on the server. Generate a report, process an uploaded workbook, or compute a formula in a background job - reading and writing .xlsx files straight from C#:

using Radzen.Documents.Spreadsheet;

var wb = new Workbook();
var sheet = wb.AddSheet("Report", 100, 10);
sheet.Cells[0, 0].Value = "Product";
sheet.Cells[1, 0].Value = "Widget";
sheet.Cells[1, 1].Value = 1200;
sheet.Cells[1, 2].Formula = "=B2*0.2";

using var ms = new MemoryStream();
wb.SaveToStream(ms);                       // write .xlsx
ms.Position = 0;
var loaded = Workbook.LoadFromStream(ms);  // read it back

No third-party Excel library and no Office install on the server.

How simple it islinkLink to this section

One package and one component. Install it from NuGet:

dotnet add package Radzen.Blazor

And put a spreadsheet on the page:

@using Radzen.Blazor.Spreadsheet
@using Radzen.Documents.Spreadsheet

<RadzenSpreadsheet Workbook="@workbook" style="height: 600px" />

@code {
    Workbook workbook = new Workbook();

    protected override void OnInitialized()
    {
        var sheet = workbook.AddSheet("Sales", 50, 26);
        sheet.Cells["A1"].Value = "Revenue";
        sheet.Cells["B1"].Value = 1000;
        sheet.Cells["B2"].Value = 1200;
        sheet.Cells["B3"].Formula = "=SUM(B1:B2)";
    }
}

That is the whole setup.

Frequently asked questionslinkLink to this section

Is there a free Blazor spreadsheet component? Yes. RadzenSpreadsheet is a free, MIT-licensed spreadsheet component for Blazor, released on June 24, 2026. Install the Radzen.Blazor NuGet package and use the RadzenSpreadsheet component.

Does it import and export Excel (XLSX) files? Yes. It opens and saves .xlsx files - load a workbook, edit it in the browser with live recalculation, and export it back to .xlsx or .csv. Formatting, multiple sheets, and frozen panes survive the round-trip.

What Excel functions does it support? Over 100, across aggregation (SUM, SUMIF, SUMIFS, SUBTOTAL), lookup (VLOOKUP, HLOOKUP, XLOOKUP, INDEX, MATCH), logical (IF, IFS, SWITCH), text, date and math - with more each release. You can also register your own in C#.

Does it work in Blazor WebAssembly? Yes. It works in both Blazor WebAssembly and Blazor Server. In WebAssembly, formulas and Excel import/export run entirely on the client, with no server round-trip.

Can I render custom Blazor components in spreadsheet cells? Yes. Plug in your own Blazor components as cell renderers and editors, add custom toolbar tools, and decide exactly which actions users can perform.

When was it released? It's available now, released on June 24, 2026.

Available nowlinkLink to this section

RadzenSpreadsheet is part of the open-source Radzen Blazor library, released on June 24, 2026.

Explore the live spreadsheet demos →

Like what you see? Star the repository on GitHub and follow along as we add more each release.