XLSX Viewer

How it works

This tool parses your spreadsheet file with SheetJS, a widely-used open-source library that reads .xlsx/.xls/.xlsm and several other spreadsheet formats, and displays each sheet's data with the first row as a header. Only the rows currently on screen are rendered, so browsing a sheet with tens of thousands of rows stays responsive.

Limitations

This is a viewer, not an editor — no cell editing, no formula recalculation, no charts or formatting. Export to CSV if you need the data elsewhere.

FAQ

Can I edit the spreadsheet?

No — this is a read-only viewer. You can browse each sheet and export the data you see to CSV, but editing and re-saving as .xlsx needs a spreadsheet app.

Does this support formulas?

Cells show their last-calculated values, the same numbers you'd see opening the file normally — formulas themselves aren't re-evaluated, since there's no spreadsheet engine here, just a reader.

Is my file uploaded anywhere?

No. The spreadsheet is parsed and displayed entirely in your browser — nothing is sent to a server.