XLS to XLSX
Free online XLS to XLSX converter. Files are processed locally in your browser, never uploaded.
Click or drag file here
Supports files up to 100MB
About XLS to XLSX
XLS is the legacy binary Excel 97-2003 format, increasingly awkward in modern Office, online spreadsheets, and other software. Converting to XLSX gives you smaller files, more rows and columns, and broad compatibility. The whole read-and-rebuild process happens locally in your browser—no Excel required.
How to use
Converting XLS to XLSX with Fangge takes just three steps:
1. Click the upload area above and select the XLS file from your device (or drag it onto the page);
2. Conversion starts automatically and happens entirely in your browser—your file is never uploaded;
3. When it finishes, click "Download File" to save the XLSX file locally.
Why convert XLS to XLSX?
Interoperability: Excel, WPS, LibreOffice, and business systems favor different formats—conversion keeps your data moving through every step;
Right format for the job: XLSX keeps styles, formulas, and multiple sheets, while CSV is perfect for system integration;
Ready to deliver: spreadsheets to PDF lock the layout for formal reports and archives;
No software needed: works in your browser without Excel or LibreOffice.
XLS to XLSX FAQ
Is XLS to XLSX conversion free?
Yes. Fangge is completely free, requires no registration, and has no conversion limits or hidden fees.
Will the converted XLSX file keep the original formatting?
Conversion focuses on extracting text content. Basic structures like headings and paragraphs are preserved where possible; images, complex tables, and multi-column layouts may be simplified.
Is my file uploaded to a server?
No. All conversion happens locally in your browser. Your file data never leaves your device, making the process private and secure.
Is there a file size limit?
Files up to 100MB are supported, which covers the vast majority of e-books and office documents.
How do I save the file when converting to PDF?
When the target format is PDF, a nicely formatted print page opens after conversion. Use your browser's "Print → Save as PDF" to save the file—the text stays selectable and CJK characters render perfectly.