XLSX to XLS converter
Convert XLSX files to XLS with TLS uploads and automatic deletion. Legacy binary Microsoft Excel format, predating XLSX.
Drop a XLSX file, or click to browse
Converts to XLS · runs live, right now
How it works
Drop your file
Drag a XLSX file in, or click to browse. No account needed to try it.
We convert it
Secure upload, converted to XLS in our sheet pipeline.
Download the result
Grab your XLS file immediately, or find it later in your dashboard.
Why convert XLSX to XLS?
XLS is a plain, uncompressed format — the file will likely be larger than the XLSX original, in exchange for maximum compatibility. The main reason to convert XLSX to XLS is compatibility: XLS opens cleanly in Excel, Google Sheets and most spreadsheet tools, while XLSX doesn't always. If you're sharing a file with someone else, sending it to a tool that expects a specific format, or archiving it for the long term, XLS is usually the safer target.
Format comparison
| XLSX | XLS | |
|---|---|---|
| Extension | .xlsx | .xls |
| MIME type | application/vnd.openxmlformats-officedocument.spreadsheetml.sheet | application/vnd.ms-excel |
| Compression | lossless compression | no compression scheme of its own |
| Category | spreadsheet | spreadsheet |
Common reasons to convert XLSX to XLS
- Importing data into a tool or script that only reads XLS
- Sharing a spreadsheet with someone who doesn't have XLSX's original app
- Maximizing compatibility with older or stricter tools that expect an uncompressed XLS file
Your file, handled carefully
Uploads use TLS in transit and AES-256 SSE-S3 at rest in production (when the production S3 credential gate is enabled), are processed in an isolated job, and deleted on the schedule you choose — as fast as immediately. We don't index, search, or share files between accounts. Read the full security model →
Frequently asked questions
Is converting XLSX to XLS free?
Yes — the Free plan includes 50 conversions every month, including XLSX to XLS. Paid plans raise that limit.
Will I lose quality converting XLSX to XLS?
XLS is legacy binary microsoft excel format, predating xlsx. We use the highest-quality encoder settings by default so visual or data loss is minimized.
Do you keep a copy of my file?
Files are deleted automatically based on your plan's retention options. Free accounts can keep results for 1h or 24h; Pro and above add options such as delete-immediately and 7 days.
What is XLSX?
Microsoft Excel's XML-based spreadsheet format.
What happens if a conversion fails?
You get a clear error message and the job is marked failed in your history — we never silently drop a file. Retry is one click. Monthly quotas count attempts (including failures) because processing starts as soon as the job is created.