What is the XLR file format?
.xlr is a spreadsheet document associated with Microsoft Works. The format uses the standard spreadsheet data layout but is somewhat limited in the amount of data a single file can accommodate and process compared to modern formats. .xlr documents support features such as formula creation, charting tools, and basic image processing. Microsoft Works was a more limited alternative to the popular Microsoft Office Excel application, aimed at home and small-business users.
Internally, Works 7-9 stored .xlr files using the same BIFF8 binary format as .xls, wrapped in an OLE2 Compound Document container - which is why Microsoft Excel 2003 and earlier could open many .xlr files directly. Excel 2007 and later dropped built-in .xlr support; a Works converter add-in existed briefly but is no longer available. LibreOffice Calc can open most .xlr files as a free alternative.
Microsoft Works was a lightweight alternative to the Office suite, sold from 1987 to 2009. In 2010, Microsoft discontinued Works and replaced it with the Office 2010 Starter Edition. Works 9 (2007) was the final version to produce .xlr files. The format's grid limit is 256 columns × 65,536 rows - identical to the Excel 97-2003 BIFF8 constraint. Microsoft never published a formal specification for .xlr, and the format has no active successor.
Security & safety
RISK: LOWXLR files share OLE2 structure with Office documents and could theoretically embed macros, but Microsoft Works did not support VBA macros - XLR files carry no macro execution risk. Standard caution applies when opening files from unknown sources.
Format details
in a nutshellPrograms that open XLR files
Windows2 apps
Microsoft Excel
Paid Rename the file from .xlr to .xls, then open in Excel. Works reliably for Works 7-9 files (BIFF8-compatible). Excel 2007+ dropped native .xlr filter. 
LibreOffice Calc
Open-source File → Open, select the XLR file. LibreOffice reads the OLE2/BIFF structure directly. Best free option. 
macOS2 apps
Microsoft Excel (macOS)
Paid Rename .xlr to .xls and open - macOS Excel (2016+) may open it, compatibility not guaranteed. Technical details
deep spec| Container format | OLE2 Compound Document (Microsoft Compound Binary File Format); magic bytes `D0 CF 11 E0 A1 B1 1A E1` at offset 0 |
| Internal binary format | BIFF8 (Binary Interchange File Format) Workbook stream - same as Excel 97-2003 `.xls` |
| Works version compatibility | Works 4.x-6: proprietary Works BIFF variant; Works 7-9: BIFF8-compatible (opens in Excel 2003 and earlier) |
| Byte order | Little-endian |
| Grid dimensions | Maximum 256 columns × 65,536 rows (identical to Excel 97-2003 / BIFF8 limits) |
| Supported features | Formulas, charts, basic image embedding, password protection |
| Excel compatibility | Excel 2003 and earlier: native support; Excel 2007 and later: dropped built-in support (converter add-in no longer available) |
| Alternative opener | LibreOffice Calc can open most `.xlr` files without a converter |
| Encryption | Optional password protection using the same OLE2 encryption mechanism as Office 97-2003 |
| Operating system | Windows only; Microsoft Works was never released for macOS or Linux |
| Discontinuation | Works discontinued January 2010; Works 9 (2007) was the last version to produce `.xlr` files |
| Public specification | None published by Microsoft; the format is de facto BIFF8 under OLE2 with a renamed extension |
| Released | 1987 (Microsoft Works 1.0 for DOS); XLR extension introduced with Works for Windows, widely used Works 4.x-9 |
| Latest version | Microsoft Works 9 (2007) - last version to produce XLR files |
XLR conversions
Community Q&A
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