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XLS Converter
Convert XLS files on your own machine instead of an upload form. reaConverter processes everything locally, with no size limits.
How to Convert .xls Files in Bulk
1. Install reaConverter
2. Select XLS Files
3. Start Conversion
Step by step
See It in Action
For quick and effortless XLS file handling on your PC, reaConverter offers powerful conversion tools with batch processing. Best of all, it works entirely offline — ensuring your sensitive data never leaves your computer.
Extra Tools
Do more with your documents
Converting XLS documents for use in a larger project? reaConverter offers many ways to process documents, so you can customize them according to your requirements.
Our range of editing options includes auto-processing options such as auto-rotate, auto-crop, watermarking and more. Change Color Space, copy Metadata, set DPI, manage ICC Profile, control Bit Depth.
User reviews
From those who tried it
Average User Rating:Last updated on July 28, 2026
Questions & Answers
XLS documents: Frequently Asked Questions
What are XLS files?
XLS is the binary spreadsheet format that Excel used by default from Excel 97 to Excel 2003. It is known as BIFF8, short for Binary Interchange File Format, and the data are stored as a sequence of records in an OLE compound file, which describe the workbook, the sheets, the cells with their values and formulas, the formatting, and the charts. The format has firm limits: a worksheet can hold at most 65,536 rows and 256 columns, the last column being IV, the number of colors in a workbook is limited to 56, and a cell can have only three conditional formatting rules. If a newer workbook with more rows is saved as XLS, the data beyond the limit are dropped. VBA macros can be stored in the file. An XLS file is usually larger than an XLSX file with the same content, and it has fewer chart types and features. Programs that cannot work with Open XML often still read it, which is why it is used for exchange with old software. Supported by Microsoft Excel.
Can reaConverter open XLS files?
reaConverter fully supports the XLS document format – open, edit, and export XLS files to any other popular file format with ease.
How do I change XLS to another format?
reaConverter is a user-friendly tool for converting XLS files. Once installed on your computer, it allows you to convert all your .xls files at once with just a few clicks. You can even convert XLS documents directly from Windows Explorer using the right-click menu — fast and convenient.
Why choose offline conversion with reaConverter?
Keep your sensitive data 100% private with offline processing that never exposes files to cloud risks. Our software meets strict compliance standards (GDPR, HIPAA, CCPA) while handling confidential documents for legal, healthcare and financial sectors.
Can I convert XLS online?
If you only want to convert a few XLS documents, you are welcome to try our free online XLS converter.
How can I turn XLS files on my computer to another format?
The best way to convert XLS documents on your PC is to get a quality piece of software, such as reaConverter. This software is extremely efficient in managing a wide range of batch files conversions, including conversion from XLS.
How can I automate XLS files conversion?
reaConverter supports all the essential automation features, such as right-click сonversion and Watch Folders, for the most efficient automated file conversion in any software of its kind.
Can I convert XLS files using scripts or the command-line interface?
reaConverter provides full access to all its features from the Windows command-line shell, including the command-line xls converter.
What else can I do with reaConverter?
Convert microscopy filesResize picturesConvert Gerber imagesConvert RGB to CMYKConvert raster to vector
What formats can I convert a XLS file to?
Discover More
Beyond XLS conversion
Convert .xls files in batches of any size, with editing and processing applied along the way. The same tool also handles 800+ other formats, including CAD, medical imaging, and GIS.
