Convert your .xlsx files to .xls format online for free. No software to install. Fast, secure, and easy.
Free — 3 conversions per day
Drag and drop your .xlsx file or click to browse.
Select XLS as your output format.
Click Convert and download your .xls file.
Converting from XLSX (Office Open XML Spreadsheet) to XLS (Microsoft Excel Binary Spreadsheet) helps you work with your content in a different application or workflow. XLSX and XLS serve different purposes, and converting between them bridges the gap.
XLSX (Office Open XML Spreadsheet, introduced in 2007) uses ZIP (containing XML parts) compression. XLS (Microsoft Excel Binary Spreadsheet, introduced in 1987) uses None (OLE2 compound binary) compression. XLSX browser support: None (requires office application or online viewer). XLS browser support: None (requires office application).
The quality impact depends on the specific settings used during conversion. XLS uses compression that may affect quality depending on the chosen settings.
Typical XLSX file size: A 10,000-row spreadsheet with formulas: ~500 KB - 2 MB. Typical XLS file size: A 10,000-row spreadsheet: ~1-5 MB.
For the best conversion results, always start from the highest quality source file available. Converting from a previously compressed file compounds any existing compression artifacts. When in doubt, use higher quality settings — you can always re-convert at lower quality later, but you cannot recover quality that has been lost.
Convert XLSX to XLS with 3 free conversions per day. No hidden fees.
Create a free account in 10 seconds and start converting immediately. No credit card required.
Files are encrypted during transfer, processed on secure servers, and deleted immediately after conversion.
Convert files from any device — desktop, tablet, or phone. No software to install, works in any modern browser.
SquishConvert supports over 358 file conversion combinations across images, documents, audio, and video.
Your converted .xls file maintains the best possible quality. No unnecessary compression or quality loss.
You get 3 free conversions per day. Upgrade to Pro for unlimited conversions.
Most files convert in under 10 seconds. Larger files may take a bit longer depending on size.
Yes. Files are encrypted during transfer, processed on secure servers, and deleted immediately after conversion. We never store your files.
Currently, SquishConvert converts one file at a time. Batch conversion is coming soon — stay tuned!
Free users can convert files up to 10 MB. Pro users can convert files up to 500 MB.