What Is an XLSB File?

An XLSB file is an Excel Binary Workbook. It is a spreadsheet format created by Microsoft Excel that stores data in a compact binary structure instead of the XML-based format used by standard XLSX files. The XLSB format was introduced in Excel 2007 alongside XLSX, XLSM, and other Office Open XML formats.

XLSB vs XLSX — What Is the Difference?

Both XLSB and XLSX are Excel file formats, but they store data differently. XLSX files use XML text files compressed in a ZIP archive. XLSB files use a proprietary binary encoding, also compressed in a ZIP archive. This binary encoding makes XLSB files meaningfully different in practice:

When Are XLSB Files Used?

XLSB files are most common in industries that work with very large spreadsheets. Financial institutions, insurance companies, and enterprise reporting teams often prefer XLSB because it handles hundreds of thousands of rows more efficiently than XLSX. If you work with large data exports from SAP, Oracle, or similar enterprise systems, you may encounter XLSB files regularly.

How to Open XLSB Files Without Excel

If you do not have Microsoft Excel installed, your options for opening XLSB files are limited. LibreOffice Calc can open them, but it is desktop software you need to install. Google Sheets does not support XLSB at all. Most online spreadsheet viewers only handle XLSX and CSV.

XLSB Viewer solves this by letting you open XLSB files directly in your web browser. It uses WebAssembly to parse the binary format at near-native speed, and everything runs on your device so your data stays private.

Can I Convert XLSB to Other Formats?

Yes. With XLSB to JSON conversion, you can export your spreadsheet data as structured JSON in three formats: records, array, or columnar. This is useful for importing data into web applications, databases, or data analysis tools.