All about XLR files

Microsoft Works spreadsheet format, closely related to XLS

Last updated on April 25, 2026 by Sören Ramspeck with the experience of more than 128,396,078 converted files since 2013.

XLR files are spreadsheets created using Microsoft Works. XLR files therefore contain typical spreadsheet data such as cells in rows and columns, NUMBERS, formulas, and charts. Unlike XLS and XLSX files, XLR files support significantly fewer features: no macros, no VBA, and usually only one sheet per file. Things used to be a bit simpler back then.
So anyone who stumbled upon an XLR file while cleaning up is now occasionally faced with a problem: Works? Doesn’t exist anymore. Excel? According to Microsoft, preferably only available via subscription.

History lesson: Works as an affordable alternative to Office

I still remember Works well, because my first computers had Works pre-installed; “Office” was for professionals back then. So, to understand the XLR format, you have to understand Microsoft Works. Works was Microsoft’s affordable entry-level version. Works included a word processor, a spreadsheet, and a database, and was primarily aimed at home users, clubs, and small businesses. Because of its low price, Works was often pre-installed on affordable pre-built PCs and thus found its way into many households, often without users having consciously chosen it.
Works was discontinued in 2009. The official Microsoft lifecycle entry on Microsoft Learn lists January 8, 2013, as the end of mainstream support for Microsoft Works overall; for Works 9, this ended as early as October 9, 2012. Works was replaced by the stripped-down Office 2010 Starter Edition, which, however, also did not last long.

Technical Details: What’s Inside an XLR File?

Excel-based binary format

In short: XLR is not a standalone format and is based—who would have guessed—on XLS. The newer versions of the Works spreadsheet program used the same internal binary file format as Microsoft Excel at the time, the classic BIFF-based XLS format, just with a different file extension. The most direct confirmation comes from Microsoft itself. Microsoft states that Excel 2010 could open Works files with the .xlr extension without a separate converter. The reason this worked was simply that the binary format contained within was already one that Excel recognized.

Proprietary and barely documented

Although XLR is technically closely related to XLS, the format was never publicly specified. While Microsoft itself did provide internal conversion filters for Works files (initially as part of Works, later as a separate “Microsoft Works 6-9 File Converter” for Word and Excel), the actual format details were never published as an open document.

Functional limitations compared to Excel

Works was deliberately stripped down. The Works spreadsheet did not support all the functions familiar from Excel, and automation with Visual Basic for Applications was also missing. Furthermore, a Works spreadsheet document could contain only one table at a time. The concept of multiple worksheets in a workbook, as found in Excel, did not exist in Works.

Opening XLR files today

Anyone who wants to open an XLR file today faces a paradoxical situation. The format is technically close to Excel, yet it is no longer directly supported by modern versions of Excel. The reason lies in Microsoft’s gradual removal of old import filters. In Microsoft’s official overview “File formats that are supported in Excel,” .xlr appears among the unsupported formats starting with Excel 2013. There, Microsoft advises users to either find a third-party converter or take a detour via another program that can export the file to a format supported by Excel.

The last version of Excel that could still open XLR files natively is therefore Excel 2010. On newer systems, conversion is the only option.

Converting XLR files

For most users today, the most practical method is online conversion using file-converter-online.com. The XLR file is uploaded, analyzed on the server, and converted to a modern target format. Typically, this is XLSX for further editing or PDF for archiving or viewing.

Sources

[1] Microsoft Support: Move from Microsoft Works to Office 2010
^[2] Microsoft Learn: Microsoft Works Lifecycle
^[3] Microsoft Support: File formats that are supported in Excel