XLS to Excel Converter

Convert your legacy XLS spreadsheets to modern Excel format (XLSX) instantly in your browser. 100% free, secure, and no file uploads required.

Upload XLS File

Drag & drop your XLS file here

or

Supported formats: .xls, .xlsx, .xlsm, .xlsb, .csv

Max file size: No limits (browser dependent)

Convert to Excel

Upload a file to begin conversion

Why Choose Our Converter?

100% Secure

Files never leave your browser. No server uploads, no privacy concerns.

Preserve Formatting

Maintain all your original data, formulas, and formatting during conversion.

Lightning Fast

Convert files in seconds with our optimized browser-based processing.

How to Convert Your Files

1

Upload File

Drag & drop or select your XLS file

2

Click Convert

Initiate the conversion process

3

Processing

File converts in your browser

4

Download

Get your Excel file instantly

Free XLS to Excel Conversion Tool

Welcome to our completely free XLS to Excel converter! This powerful tool allows you to convert legacy Microsoft Excel 97-2003 (.xls) files to the modern Excel format (.xlsx) directly in your browser. No installations, no registrations, and absolutely no cost.

Why Convert XLS to XLSX?

The XLS format was used by Microsoft Excel from 1997 to 2003. The newer XLSX format offers several advantages:

  • Smaller file sizes - XLSX files are typically 50-75% smaller than equivalent XLS files
  • Better data recovery - XML-based format is less prone to corruption
  • Improved security - Reduced risk of macro viruses
  • Enhanced features - Support for modern Excel functions and larger spreadsheets
  • Compatibility - Works better with modern software and cloud services

How Our Tool Benefits You

Our converter provides a seamless solution for anyone needing to update old spreadsheet files:

  • Business Professionals - Update financial reports and data sheets
  • Researchers & Academics - Convert research data for modern analysis tools
  • Administrative Staff - Modernize record-keeping and documentation
  • Students - Ensure compatibility with school requirements
  • Archivists - Preserve historical data in modern formats

Complete Privacy Guaranteed

Unlike other online converters, your files never leave your computer. All processing happens directly in your browser using JavaScript. This means:

  • No file uploads to external servers
  • No risk of sensitive data exposure
  • No storage of your files on any server
  • Complete control over your data

Frequently Asked Questions

Is this tool really free?

Yes, absolutely! Our XLS to Excel converter is 100% free to use with no hidden costs or limitations. We believe in providing valuable tools without charging our users.

Are my files secure?

Completely secure. Your files never leave your computer. All conversion happens locally in your browser using JavaScript. We don't have access to your files at any point.

What's the maximum file size I can convert?

There are no artificial limits. The actual limit depends on your browser's memory capacity. Most modern browsers can handle files up to 500MB, but very large files may cause performance issues.

Does this work on mobile devices?

Yes! Our converter is fully responsive and works on smartphones, tablets, and desktop computers. The interface adapts to your screen size for optimal usability.

What features are preserved during conversion?

Our converter preserves all data, formulas, formatting, charts, and basic macros. Some extremely complex macros may require adjustment after conversion.