Need to Share Excel Files with Older Systems?
You created a spreadsheet in a modern version of Excel, but the person you're sending it to can't open it. Their computer runs Excel 2003 or earlier, and those versions don't recognize the newer XLSX format that's been standard since 2007.
Converting your XLSX files to XLS takes seconds and solves the problem completely. XLS is the format that works with every version of Microsoft Excel ever made - including the older ones that many businesses and individuals still use today.
How to Convert XLSX to XLS
- Upload your XLSX file - Drag and drop or click to select your modern Excel spreadsheet
- Confirm XLS output - The legacy Excel 97-2003 format is selected for maximum compatibility
- Download your file - Your spreadsheet is now compatible with all Excel versions
No Microsoft Office installation required. No account to create. Just convert and download.
Why XLSX Files Don't Open on Older Systems
Microsoft introduced the XLSX format in 2007 with Office 2007. It replaced the older XLS format that had been used since Excel 97. While this was a technical improvement, it created a compatibility divide:
- Excel 2003 and earlier - Cannot open XLSX files without special compatibility packs
- Legacy business systems - Many older accounting and ERP systems only accept XLS
- Government and institutional computers - Often run outdated software for security or budget reasons
- Older third-party applications - Import tools and integrations may only support XLS
In our testing, we've found that organizations with strict IT policies often maintain Excel 2003 installations years beyond their typical lifecycle. Converting to XLS ensures your files work regardless of the recipient's software version.
XLSX vs XLS: Technical Differences
Understanding the differences between these formats helps explain why conversion is sometimes necessary:
| Feature | XLSX (Modern) | XLS (Legacy) |
|---|---|---|
| Excel Versions | 2007 and later | All versions (97-2003 native) |
| Maximum Rows | 1,048,576 | 65,536 |
| Maximum Columns | 16,384 (XFD) | 256 (IV) |
| File Format | Compressed XML | Binary (BIFF8) |
| File Size | Smaller | Larger |
| Macro Support | No (use XLSM) | Yes |
The most important limitation when converting from XLSX to XLS is the row limit. If your spreadsheet has more than 65,536 rows or 256 columns, data beyond these limits will be truncated. In our testing, files with fewer than 60,000 rows convert without any issues.
Common Use Cases for XLSX to XLS Conversion
Sharing with Clients on Older Systems
You send a financial report to a client, but they email back saying they can't open it. Their office still runs Excel 2003. Converting to XLS before sending eliminates this back-and-forth.
Importing into Legacy Software
Many accounting systems, inventory management tools, and database applications built before 2007 only accept XLS file imports. Converting lets you use modern Excel for editing while maintaining compatibility with these systems.
Government and Institutional Submissions
Some government agencies and large institutions specify XLS format for data submissions. Their processing systems may not have been updated to handle XLSX files.
Archive Compatibility
If you're archiving spreadsheets for long-term storage and want to ensure they'll open on any system in the future, XLS provides broader compatibility across older software that may still be in use.
What Gets Preserved During Conversion
When you convert XLSX to XLS, your spreadsheet content transfers intact:
- Cell data and formulas - Numbers, text, dates, and calculations remain accurate
- Formatting - Cell colors, fonts, borders, and conditional formatting carry over
- Multiple sheets - Workbooks with several tabs convert as complete files
- Charts and graphs - Basic visualizations transfer to the legacy format
- Print settings - Page layouts and print areas are maintained
In our testing, standard business spreadsheets - budgets, reports, data tables, invoices - convert without any visible differences. Complex files with newer Excel 2013+ features may have some elements simplified to match XLS capabilities.
Limitations to Know About
Converting from XLSX to XLS means moving to an older format with certain constraints:
- Row limit - XLS supports 65,536 rows maximum. Larger datasets will be truncated
- Column limit - XLS supports 256 columns (A to IV). Extra columns are removed
- Newer features - Sparklines, slicers, and features added after Excel 2003 may not convert
- File size - XLS files are typically larger than their XLSX equivalents due to lack of compression
For most business documents, these limitations don't matter. If your spreadsheet fits within 65,000 rows and uses standard features, conversion works seamlessly.
Alternative Formats to Consider
Depending on your specific needs, other formats might work better:
- XLSX to CSV - If you only need the data without formatting, CSV works with virtually any software and has no row limits
- XLSX to PDF - For sharing spreadsheets that recipients should view but not edit
- XLS to XLSX - If you need to go the other direction, modernizing legacy files
Choose XLS specifically when the recipient needs to edit the file in an older Excel version.
Works on Any Device
Convert XLSX to XLS directly in your browser:
- Windows, Mac, Linux, Chromebook
- Chrome, Firefox, Safari, Edge
- Tablets and mobile devices
No software downloads. No installations. Your files stay on your device during the conversion process.
Batch Conversion for Multiple Files
Have a folder full of XLSX files that need converting? Upload multiple spreadsheets at once and convert them all to XLS format in a single batch. No need to process files one at a time when you're preparing documents for a legacy system import or archive project.