Data converter · runs 100% in your browser
JSON to XLSX Converter
Build an Excel file from JSON. Arrays of objects become sheets; nested objects of arrays become multi-sheet workbooks. The whole conversion runs in your browser via SheetJS — no upload, no signup, no row limit.
How to use
- Drop your JSON file.
- Click Convert.
- The converter parses the file locally and produces XLSX.
- Click Download.
FAQ
Are formulas evaluated?
Cell values are exported as their last-saved values, not as formulas. If a formula was unevaluated when the file was saved, the result will be empty.
Does my spreadsheet upload to a server?
No. Conversion runs entirely in your browser using WebAssembly and Web APIs. Open the Network tab in DevTools while you convert — you'll see no outbound traffic carrying your file.
Is this really free?
Yes. No signup, no quota, no upgrade tier. The conversion runs on your machine, so it costs us nothing to host.
Is there a file size limit?
Browser memory is the only ceiling. On a modern desktop browser, a few hundred megabytes works fine. Mobile devices have tighter limits.