Convert XLS to XLSX
Drop your XLS and get XLSX back in seconds. Our AI handles the conversion — no settings, no software, nothing to learn.
Talk to your files
Anything that used to take five menus and three export dialogs is now one sentence in the chat. Watch it work:
Built for how you actually work
One assistant instead of a dozen single-purpose converter sites.
Every format in one place
Images, documents, video, audio and data — 50+ formats handled by one chat, with a dedicated page for every conversion.
Private by design
Your files are used to run your conversion and nothing else. No sharing, no training, and everything auto-deletes within 24 hours.
Seconds, not minutes
Most conversions come back before you'd have found the right export menu.
Speaks your language
The whole product — pages, assistant and answers — works in seven languages.
Nothing to install
Runs entirely in your browser, on any device. No apps, no accounts to start, no updates.
XLS vs XLSX at a glance
| XLS | XLSX | |
|---|---|---|
| Type | Spreadsheet | Spreadsheet |
| File extension | .xls | .xlsx |
| Support | Specific apps only | Most apps and devices |
| Best for | Legacy Excel files | Spreadsheets with formulas and formatting |
What is a XLS file?
XLS is Excel's pre-2007 binary format. Modern Excel still opens it, but the format caps out at 65,536 rows, chokes modern tooling, and is best migrated away from.
What is a XLSX file?
XLSX is Excel's native format: multiple sheets, formulas, charts, formatting and proper data types in one file. Google Sheets, LibreOffice and Numbers all open it too.
Why convert XLS to XLSX?
XLS is a legacy binary format capped at 65,536 rows that modern tools increasingly refuse. XLSX opens straight into Excel or Google Sheets with data types, multiple sheets and formatting intact.
XLS to XLSX, answered
Common questions about converting XLS to XLSX.
Drop your XLS into the chat and ask to convert it to XLSX. The assistant runs the conversion and gives you a XLSX to download — usually in a second or two.
Yes. You can convert XLS to XLSX for free as a guest. Signing in raises your limits and lets you convert more files per day.
No. Everything runs in your browser — there's nothing to download or set up. Just drop your XLS and go.
Your XLS is only used to run the conversion you asked for. We don't share it or use it for anything else, and it's automatically deleted from our servers within 24 hours.