The short version
XLSX Viewer opens and converts your files inside your browser. The file is read in your device’s memory and is never sent to a server. There are no accounts, and the site’s own code sets no cookies. We do not run analytics or advertising scripts.
What happens to your files
When you open or convert a file, your browser reads it and the page’s own scripts process it. The code that does this, including the spreadsheet library, is served from this site rather than from a third party. Results you download are created on your device.
What this site stores in your browser
- Your theme choice (light or dark), so the page looks the same next time.
- Open tabs of the viewer. So your work survives a refresh, the viewer keeps your open files, and any edits you made, in your browser’s own storage on this device. Closing a tab deletes its saved copy.
- Tool settings such as the options you last chose on a converter. They live in the browser’s local storage and carry no file contents.
- A saved copy of the site (the service worker cache), so pages and tools open without a connection.
None of this is sent to us. You can remove it at any time: choose Clear saved data in the ⋯ menu, or clear this site’s data in your browser settings.
What the server sees
Like any website, the server that hosts these pages receives a request each time a page or script is loaded, and a web host normally keeps standard access logs (time, address, page requested). Your files and what you type into the tools are not part of those requests.
This site does not use analytics, advertising or tracking cookies, and it loads no scripts from other companies. The site owner uses Google Search Console to see which searches lead to these pages. That information comes from Google’s own search results, not from anything running on these pages, so it never includes your files or what you type.
How to check this yourself
- Open the developer toolsIn most browsers, press F12 and choose the Network tab.
- Open a fileAdd a spreadsheet to the viewer or any converter and watch the list.
- Look for uploadsYou should see no request that carries your file. For a longer test with the connection switched off, see the offline and privacy page.
Changes to this page
If this site ever adds analytics, advertising, a feedback form or any other way for data to leave your device, this page will say exactly what is collected, which companies receive it and how to opt out, before it goes live. Your files will stay on your device either way. Last reviewed on 1 November 2026.