Convert your .xls files to .xlsx format online. No software to install.
Free account: 10 conversions a month. Pro: 100 a month.
Drag and drop your .xls file or click to browse.
Select XLSX as your output format.
Click Convert and download your .xlsx file.
Converting from XLS (Microsoft Excel Binary Spreadsheet) to XLSX (Office Open XML Spreadsheet) helps you work with your content in a different application or workflow. XLS and XLSX serve different purposes, and converting between them bridges the gap.
XLS (Microsoft Excel Binary Spreadsheet, introduced in 1987) uses None (OLE2 compound binary) compression. XLSX (Office Open XML Spreadsheet, introduced in 2007) uses ZIP (containing XML parts) compression. XLS browser support: None (requires office application). XLSX browser support: None (requires office application or online viewer).
The quality impact depends on the specific settings used during conversion. XLSX uses compression that may affect quality depending on the chosen settings.
Typical XLS file size: A 10,000-row spreadsheet: ~1-5 MB. Typical XLSX file size: A 10,000-row spreadsheet with formulas: ~500 KB - 2 MB. Expect a dramatic file size reduction — often 5-20x smaller — when converting from uncompressed XLS to XLSX.
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.
Free account: 10 conversions a month. Pro: 100 a month. No watermarks.
Create a free account in 10 seconds and start converting immediately. No credit card required.
Your file is sent over an encrypted connection to our provider CloudConvert, which converts it and deletes it after the conversion, within 24 hours at most. Details in our Privacy Policy.
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 .xlsx file maintains the best possible quality. No unnecessary compression or quality loss.
Free account: 10 conversions a month. Pro: 100 a month.
It depends on the file size and on the queue at our provider. Small files usually take a few seconds.
Your file is sent over an encrypted connection to our provider CloudConvert, which converts it and deletes it after the conversion, within 24 hours at most. Details in our Privacy Policy.
Free users can convert files up to 10 MB. Pro users can convert files up to 500 MB.