Convert Excel to CSV or JSON
Useful when a spreadsheet has to go into a script or a database and you would rather not send the company’s numbers to a conversion site.
- Runs entirely in your browser
- Works offline
- No upload
- No sign-up
- No watermark
Loading the tool…
How it works
- Drop an .xlsx or .xls file.
- Check the preview and choose the output format.
- Download the result.
Why nothing is uploaded
Every operation on this page is done by code running inside your browser tab, using the same engine that renders web pages. The file is read from disk into your tab’s memory, transformed there, and written back out as a download. It is never sent anywhere — not to us, not to a third party.
Verify it yourself
- Open your browser’s developer tools (F12) and select the Network tab.
- Load your file and run the tool.
- The only requests you will see fetch the tool’s own code — and, for a few heavy tools, their open-source engine from a public CDN — plus one small page-view ping to loreatec.jp (page address and title, nothing more). None of them carry your file.
Frequently asked questions
Do old Japanese .xls files work?
Yes. The legacy codepage tables are loaded, so Shift-JIS column names and values come through intact instead of as mojibake.
Are formulas evaluated?
No — the cached result value stored in the file is used, which is what the spreadsheet was showing when it was last saved. Formulas themselves are not recalculated in the browser.
Is my document uploaded?
No. The file is read and converted inside this browser tab, on your own device. You can open the page, turn off the internet, and it still works. For a contract or a customer list, that is the guarantee that matters.