Free XLSX to XLS Converter: No Sign-up, Files Never Uploaded
Convert XLSX to XLS free, right in your browser. There is no sign-up or login, no watermark, and nothing is uploaded: your spreadsheets never leave your device.
The workbook is read cell by cell and the values are written out again as XLS.
This pair runs on code that is already in the page, so there is no extra engine to download.
- Free
- No sign-up
- Never uploaded
- No watermark
Your files are converted on your device and never uploaded.
How to convert
- Add your XLSX files by dragging them onto the converter or by using the file picker.
- Check that XLS is the selected target format; it is already chosen on this page.
- Open the options if you want to change delimiter, encoding and sheet, or keep the defaults.
- Press Convert and watch the progress shown for each file.
- Download each result, or take them all together as one ZIP when you converted several files.
Features
- Reads .xlsx and writes .xls.
- Free, with no watermark added to the result.
- No sign-up and no login.
- Your files are never uploaded and never leave your device.
- Batch conversion with a ZIP download for several results.
- The input is recognised by its content, not only by its file name.
Supported formats
| Format | Read | Write | Notes |
|---|---|---|---|
| Excel (XLSX).xlsx | Yes | Yes | The default Excel format since 2007. |
| Excel 97-2003 (XLS).xls | Yes | Yes | The Excel format used until 2003. |
About the formats
About XLSX
The default Excel format since 2007.
A ZIP of XML files; supports multiple sheets, formulas and charts.
About XLS
The Excel format used until 2003.
Limited to 65,536 rows per sheet.
XLSX vs XLS
XLSX does not support transparency, and XLS does not.
Excel (XLSX) files use the .xlsx extension and Excel 97-2003 (XLS) files use .xls, so the converted file gets a new name with the new extension.
Privacy: how it works
- Your XLSX files stay on your device. The page reads each file with the browser's file API, converts it with code running in the tab, and hands the result back as a download. No upload happens, so there is no copy of your file on our servers to protect, delete or leak.
- There is nothing to sign up for and no login. The converter does not ask for an email address, and it does not need to know who you are to do its job.
- You can check the claim yourself: open your browser developer tools, watch the Network tab while a file converts, and you will see no request that carries your file.
Tips
- Check dates, long numbers and leading zeros in the result, because text formats store everything as plain text.
- Formulas become their values when you export to a plain format.
- Only the first sheet is exported to CSV and similar formats, so split a workbook first if you need every sheet.
- Keep the original workbook as the editable master.
Frequently asked questions
Is it really free?
Yes. There is no price, no trial, no credit card and no watermark added to your results. Ulkaa Tool does the conversion with your own device, so there is no server bill to pass on to you.
Are my files uploaded?
No. Your XLSX files are read and converted inside your browser and are never sent to Ulkaa or to anyone else. The result is created on your device and you save it from there.
Do I need an account?
No. There is no sign-up and no login. Open the page, add your files and convert. An Ulkaa account is not needed for anything on this tool.
Is there a file size limit?
No limit is set by us. The real limit is your device: the conversion uses your own memory and processor, so very large files can be slow, and a very big batch may need to be split into smaller runs.
What is the difference between XLSX and XLS?
XLSX does not support transparency, and XLS does not. Excel (XLSX) files use the .xlsx extension and Excel 97-2003 (XLS) files use .xls, so the converted file gets a new name with the new extension.
Can I convert many XLSX files at once?
Yes. Add as many files as your device can handle. Each one is converted on its own and you can download them one by one or as a single ZIP.
Will anything be lost when I convert XLSX to XLS?
The converter keeps the content of the file. Check the result once, since small differences in metadata or colour handling can happen between formats.
Can I convert XLS back to XLSX?
Yes. Open the XLS to XLSX page and use the same steps. Converting back does not undo any loss from the first conversion.
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