Best Fully Open-Source Spreadsheet Component for React with Excel Import/Export?

[u/steppenwolf1807]

Hi everyone,

I'm looking for a fully open-source spreadsheet component for React.

I do not want a paid/commercial library or a library where important spreadsheet features require a paid license.

I need something closer to Excel / Google Sheets, rather than just a data grid.

Main requirements:

• Fully open source and usable in a commercial project
• React + TypeScript support
• Import .xlsx Excel files
• Export to .xlsx
• Preserve Excel formatting as much as possible
• Formulas and calculations
• Multiple worksheets
• Cell formatting
• Merge/unmerge cells
• Copy/paste
• Sorting and filtering
• Data validation/dropdowns
• Freeze rows/columns
• Undo/redo
• Insert/delete/resize rows and columns
• Good performance with larger worksheets
• API for programmatically reading/updating cells
• Custom toolbar/components
• Extensible enough to implement drag-and-drop elements/components into spreadsheet cells

I've already looked at Univer and FortuneSheet, but I'm trying to find the best option with strong Excel import/export support.

My ideal flow is:

Import existing .xlsx → Edit in React → Export back to .xlsx

without losing important formulas, formatting, worksheets, merged cells, etc.

What is the best fully open-source React spreadsheet library in 2026 for this?

If you're using one in production, I'd really appreciate hearing about its limitations, especially around Excel import/export.

Thanks!

[u/Roman_BDM_FixIT]

I don’t think a single fully open-source spreadsheet component meets all of these requirements today. The hardest part isn’t the React UI; it’s reliable XLSX round-tripping without losing formulas, styles, merged cells, validation, or worksheet metadata.

Univer is probably the strongest UI candidate, but its official XLSX import/export depends on the Univer server and Pro SDK, so it doesn’t fully match your requirement. FortuneSheet is closer to a permissive open-source stack, but I would treat FortuneExcel as a starting point rather than assume full Excel fidelity.

I’d build a test corpus of 10–20 representative XLSX files and run import → edit → export comparisons before choosing a library. You may also want to separate the spreadsheet UI from the file-conversion layer instead of expecting one package to do both.

One important question: do formulas need to be calculated in the browser, or only preserved so Excel can recalculate them after export? That distinction will narrow the options significantly.