Convert XLSX to XLS
Free and instant — your XLSX files are processed securely on our servers and deleted right after conversion. Nothing is stored.
How to convert XLSX to XLS
- Step 01
Add your XLSX files
Drop them into the box above or click to browse. You can add several files at once.
- Step 02
Conversion starts instantly
Your file is sent to our servers, converted and deleted right away — no sign-up, no queue, no waiting.
- Step 03
Download your XLS files
Save each file individually or grab them all at once. Done.
Why convert XLSX to XLS?
Converting XLSX to XLS saves a modern Excel spreadsheet back into the legacy binary format — useful when you need to open it in Excel 97-2003 or older software that has never been updated to read XLSX.
XLSX vs XLS at a glance
XLSX is the standard spreadsheet format — rows, columns, formulas and charts in a file every version of Excel and most office suites can open and edit. XLS is the legacy Excel format — a binary file superseded by XLSX in 2007, still floating around in old templates and archives.
| Property | XLSX | XLS |
|---|---|---|
| Extension | .xlsx | .xls |
| Full name | Microsoft Excel Spreadsheet | Microsoft Excel 97-2003 Spreadsheet |
| First released | 2007 | 1987 |
| Developed by | Microsoft | Microsoft |
| Compression | Lossless | Lossless |
| Transparency | No | No |
| Animation | No | No |
| Best for | editable spreadsheets, data tables and financial reports compatible with Microsoft Excel | old Excel spreadsheets from Office 97-2003 that newer apps struggle to open |
XLSX to XLS — frequently asked questions
Is this XLSX to XLS converter really free?
Yes — completely free, with no sign-up, no watermarks and no daily limits.
Why would I need the old XLS format?
Some legacy systems, old versions of Excel or specialized software only accept the binary .xls format and reject XLSX files.
Is the conversion private?
Your XLSX is sent to our servers, converted using LibreOffice, and the result is returned to you. Your file is deleted immediately after conversion and never stored.
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