Convert XLS to XLSX

Free online XLS Spreadsheet to XLSX Spreadsheet converter — no signup, no watermark, instant results

Drag & drop your XLS file here
or click to browse your computer
XLS → XLSX
Convert XLSX to XLS instead
100% Free
No Limits
Privacy
Auto-Delete
Speed
<30 Seconds

XLS to XLSX Converter

Need to convert XLS Spreadsheet (.xls) files to XLSX Spreadsheet (.xlsx) format? Our free online XLS to XLSX converter makes it easy. Simply upload your file, and we'll handle the rest — delivering a high-quality XLSX file in seconds.

The XLS to XLSX conversion is one of the most popular document format conversions. Whether you're a designer, developer, content creator, or everyday user, converting between these formats is essential for compatibility, sharing, and optimization across different platforms and devices.

Our converter processes files directly in your browser using cutting-edge web technology. This means your files never leave your device unless absolutely necessary, ensuring maximum privacy and security. We support files up to 100MB in size with no daily conversion limits.

How to Convert XLS to XLSX

1
Upload your XLS file
Drag and drop your XLS Spreadsheet file onto the upload area above, or click to browse and select the file from your device.
2
Automatic conversion
Our tool instantly processes your XLS file and converts it to the XLSX format with optimal quality settings.
3
Download your XLSX file
Once the conversion is complete, click the download button to save your new XLSX Spreadsheet file. It's that simple!

Document format differences: XLS is best for specific use cases, while XLSX is designed for specific use cases. Document conversion requires server-side processing to preserve formatting, fonts, and layout.

XLS vs XLSX Comparison

FeatureXLSXLSX
CompressionFormat-specificFormat-specific
Transparency SupportVariesVaries
File SizeVariesVaries
QualityFormat-nativeFormat-native
Best ForSpecific use casesSpecific use cases
Color DepthVariesVaries
XLS → XLSX Details
Source FormatXLS (XLS Spreadsheet)
Target FormatXLSX (XLSX Spreadsheet)
CategoryDocument Conversion
Max File Size100 MB
Conversion Time~10-30 sec
PriceFree
50+
Format Pairs
<30s
Avg. Conversion
Secure
Auto-Delete Files
100%
Free to Use

XLS to XLSX FAQ

How do I convert XLS to XLSX?
To convert XLS to XLSX, simply upload your XLS Spreadsheet file using the drag-and-drop area above or click to browse. Our converter will process your file and provide a download link for the XLSX Spreadsheet output. The entire process takes just seconds and works entirely in your browser.
Is the XLS to XLSX converter free?
Yes, our XLS to XLSX converter is completely free to use. There are no hidden charges, no signup required, and no watermarks added to your converted files. Convert as many files as you need without any limitations.
Will I lose quality when converting XLS to XLSX?
Our XLS to XLSX converter uses advanced algorithms to preserve the highest possible quality during conversion. While some format changes inherently involve quality adjustments (e.g., lossy compression), we optimize settings to minimize any quality loss and deliver the best results.
Is my file data safe when converting XLS to XLSX?
Absolutely. Your files are processed securely and are automatically deleted from our servers after conversion. We never store, share, or access your file content. Your privacy and data security are our top priorities.
What is the difference between XLS and XLSX formats?
XLS Spreadsheet and XLSX Spreadsheet are different file formats with distinct characteristics. XLS is typically used for specific use cases, while XLSX offers different advantages in terms of compatibility, file size, or quality. Converting from XLS to XLSX allows you to take advantage of the XLSX format's benefits while preserving your content.

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