Windows
Compatible applications
Quick Facts
Basic information about this file format
Extension
.XLSB
File Type
Excel Binary Workbook
Category
Data
Best first step
Use compatible software
Quick Summary
A practical overview of the .xlsb file format
The XLSB file extension represents the Excel Binary Workbook format, which is a specialized spreadsheet format developed by Microsoft as part of the Office suite. Unlike the standard XLSX format, which is based on the OpenXML standard and stores data in a collection of XML files within a ZIP archiv…
File extension
.XLSB
File type
Excel Binary Workbook
Category
Data
Recommended action
Open with a trusted compatible app
How to open a .xlsb file
Start with a trusted app that supports this format
- Check the file extension carefully and confirm that the file name really ends with .xlsb.
- Use software that supports this file type. If one app does not work, try another compatible program for the same platform.
- Update the application if the file was created by a newer version of the software.
- Scan files from unknown sources before opening them, especially documents, archives, scripts, installers, and executable files.
What is a .xlsb file?
File extension details and usage information
The XLSB file extension represents the Excel Binary Workbook format, which is a specialized spreadsheet format developed by Microsoft as part of the Office suite. Unlike the standard XLSX format, which is based on the OpenXML standard and stores data in a collection of XML files within a ZIP archive, the XLSB format stores information in a proprietary binary format known as BIFF12. This binary structure allows for significantly faster reading and writing speeds, making it the preferred choice for power users and data analysts who work with exceptionally large datasets, complex formulas, or massive workbooks that would otherwise lag in XML-based formats. Because the data is encoded in binary, the resulting file sizes are typically much smaller than their XLSX counterparts. XLSB files also fully support the inclusion of VBA macros, functioning similarly to the XLSM format in that regard. While highly efficient within the Microsoft Excel environment, the binary nature makes it slightly less interoperable with third-party applications or web services that are primarily designed to parse XML-based spreadsheet data.
Software Compatibility
Programs that may open or work with .xlsb files
macOS
Compatible applications
Linux
Compatible applications
Mobile
Mobile applications
Can .xlsb files be converted?
Options for saving or exporting this file to another format
In many cases, a .xlsb file can be converted by opening it in compatible software and using an option such as Save As, Export, or Convert. The available output formats depend on the file type and the application used.
- Use the original software that created the file when possible.
- Check whether the application supports exporting to common formats.
- Be careful with online converters when working with private, business, or sensitive files.
- If conversion fails, the file may be corrupted, incomplete, encrypted, or not actually a .xlsb file.
Why can't I open a .xlsb file?
Common reasons this file type may not open correctly
Wrong software
The file may require a specific program that supports the .xlsb format.
Incorrect extension
The file extension may have been renamed manually, even though the actual file format is different.
Corrupted file
The file may be incomplete, damaged during download, or transferred incorrectly.
Outdated app
Your software may need to be updated before it can open newer versions of this file format.
Frequently Asked Questions
Common questions about .xlsb files
To open a .xlsb file, use software that supports this file format.
- Microsoft Excel
- LibreOffice Calc
- Apache OpenOffice
- SoftMaker FreeOffice
- Apple Numbers
Open the file in compatible software and look for options such as Save As, Export, or Convert. If no export option is available, the file may require a specialized converter or the original application that created it.
- Verify that the file extension is correct.
- Install or update compatible software.
- Try another application that supports this format.
- Check whether the file is corrupted, incomplete, or encrypted.
A file extension alone does not guarantee whether a file is safe or unsafe. Only open files from trusted sources, scan unknown files before opening them, and be especially careful with executable, script, archive, and document files.
File safety tips
Use caution with unknown files
Only open files from trusted sources. Before opening a .xlsb file, scan it with antivirus software, verify that the file extension is expected, and avoid running unknown executable, installer, macro-enabled document, or script files.