Free · No Upload · Instant

Convert XLS to CSV Free Online — Best XLS to CSV Converter 2025

Convert XLS to CSV online for free. Fast, private Microsoft Excel 97-2003 to Comma-Separated Values converter — no upload, no signup. Works in your browser instantly.

Choose Files

or drag and drop files here

Max file size: 2GB

Your files are processed locally in your browser. Nothing is uploaded to any server.

How to Convert XLS to CSV

Upload your XLS file by clicking "Choose Files" or drag and drop it.

Select CSV as the output format.

Click "Convert Now" and download your converted file.

About XLS Format

Extension: .xls
Full name: Microsoft Excel 97-2003

About CSV Format

Extension: .csv
Full name: Comma-Separated Values

Frequently Asked Questions

Is it safe to convert XLS to CSV online?

Yes! Convert999 processes all files directly in your browser. Your files are never uploaded to any server, ensuring complete privacy and security.

How long does it take to convert XLS to CSV?

Conversion is nearly instant for most files. Large files may take a few seconds depending on your device's processing power.

Is there a file size limit?

Convert999 supports files up to 2GB. Processing happens locally, so larger files depend on your device's available memory.

Do I need to install any software?

No installation required. Convert999 works entirely in your web browser on any device.

Can I convert XLS to CSV on my phone?

Yes! Convert999 works on any device with a web browser — iPhone, Android, iPad, or desktop. No app installation required. Simply open the converter, upload your XLS file, and download the converted CSV file.

Will I lose quality converting XLS to CSV?

Convert999 uses high-quality conversion algorithms to minimize quality loss. For lossless formats, the conversion is exact. For lossy formats like images and audio, we use optimized settings that balance quality and file size.

Can I batch convert multiple XLS files to CSV?

Yes, Convert999 supports batch conversion. Select or drag & drop multiple XLS files and convert them all to CSV format at once. Each file is processed locally in your browser.

What is the difference between XLS and CSV?

Microsoft Excel 97-2003 (XLS) and Comma-Separated Values (CSV) differ in compression, compatibility, and features. XLS is optimized for its native use cases, while CSV may offer different advantages. Visit our XLS vs CSV comparison page for a detailed breakdown.

Why Convert XLS to CSV?

Advantages

✓Comma-Separated Values offers better compatibility with modern applications and workflows
✓Converting is completely free with no file size limits on Convert999
✓Your files never leave your device — 100% private and secure conversion
✓Instant conversion without waiting for server processing

Key Differences

→XLS (Microsoft Excel 97-2003) is optimized for its native use cases
→CSV (Comma-Separated Values) may offer different compression or feature set
→Choose based on your target platform, quality needs, and file size requirements

Related Conversions

XLSXLSX XLSODS XLSCSV XLSTSV XLSNUMBERS XLSXLSM XLSCSV XLSXCSV ODSCSV TSVCSV NUMBERSCSV XLSMCSV

Explore More

.xls

XLS Converter

All XLS conversions

.csv

CSV Converter

All CSV conversions

XLS vs CSV

Compare formats

Convert to CSV

All sources → CSV