About Spreadsheet Converter
Spreadsheet Converter — free, private, browser-based convert tool
Convert Excel, ODS and CSV between each other — and to HTML or JSON, on your device. It takes .XLSX, .XLS, .ODS, .CSV, .TSV and gives you CSV, VND.OPENXMLFORMATS-OFFICEDOCUMENT.SPREADSHEETML.SHEET, HTML, JSON. It runs in your browser, so the file is processed on your own device.
Why use Spreadsheet Converter
- ·Files stay on your device — nothing is uploaded
- ·No signup needed
- ·Works in any modern browser, on any OS
- ·Free daily use; Pro removes limits and watermarks
How to use it
- 1Drop a .XLSX, .XLS, .ODS, .CSV, .TSV file on the page, or click to choose one.
- 2Pick the options you want.
- 3Download the CSV, VND.OPENXMLFORMATS-OFFICEDOCUMENT.SPREADSHEETML.SHEET, HTML, JSON file.
What Spreadsheet Converter does
Convert Excel, ODS and CSV between each other — and to HTML or JSON, on your device. The result is a CSV, VND.OPENXMLFORMATS-OFFICEDOCUMENT.SPREADSHEETML.SHEET, HTML, JSON file you download directly.
How it works
ffmpeg.wasm + libvips-wasm + pdf-lib + sheetjs + mammoth, with a routing layer that picks the best engine per pair. The processing code runs inside the page, so your file is not uploaded to a server — you can confirm this in your browser's DevTools → Network tab.