How to Open an XLSB File
To open an XLSB file, double-click it on a computer that has Microsoft Excel installed, or open Excel first and choose File → Open. If you do not have Excel, free desktop apps like LibreOffice Calc can open XLSB files, while Google Sheets and Excel for the web cannot open them until you convert the file to XLSX.
That last point trips a lot of people up, so the rest of this guide walks through every reliable way to open an XLSB file on Windows and Mac, how to convert one to a more shareable format, and what to do when a file refuses to open.
What is an XLSB file?
XLSB stands for Excel Binary Workbook. Introduced with Excel 2007, it stores all of your sheets, formulas, and data in a binary format rather than the XML-based, ZIP-packaged structure that XLSX uses. Because the data is saved as raw binary instead of text-based XML, an XLSB file is usually noticeably smaller on disk and opens and saves faster, especially for large workbooks with hundreds of thousands of rows or heavy calculations.
Unlike XLSX, the XLSB format can store macros, so it behaves like the macro-enabled XLSM format in that respect. The trade-off is reach: because the contents are binary, far fewer programs and online tools can read an XLSB file directly, which is exactly why opening one is sometimes harder than it should be.
How to open an XLSB file in Excel (Windows and Mac)
Microsoft Excel for Windows and Excel for Mac (Excel 2007 and later, including Microsoft 365) fully support XLSB. The format is identical across platforms, so a file made on Windows opens cleanly on a Mac and vice versa.
Windows
- Double-click the file. If Excel is your default spreadsheet app, the workbook opens automatically.
- Or open Excel first, then click File → Open → Browse, navigate to the file, and select it. If you do not see the file, set the file-type filter to All Files or Excel Binary Workbook (.xlsb)*.
Mac
- Double-click the file to open it in Excel for Mac, or
- Launch Excel, choose File → Open, and pick the XLSB file. You can also right-click the file in Finder and choose Open With → Microsoft Excel.
If macros are present, Excel may show a security prompt at the top of the window. Only enable content from a file you trust — see how to unblock macros in Excel for the full walkthrough, and our beginner’s guide to Excel macros and VBA if you want to understand what those macros actually do.
Opening an XLSB file without Excel
LibreOffice Calc (free, Windows, Mac, Linux)
The most dependable free option is LibreOffice Calc. Download and install LibreOffice, then open Calc and choose File → Open, or right-click the XLSB file and select Open With → LibreOffice Calc. Modern versions of LibreOffice read XLSB reasonably well, though very complex formulas, charts, or VBA macros may not survive perfectly. Apache OpenOffice Calc offers similar but generally weaker XLSB support, so LibreOffice is the better first choice.
Google Sheets cannot open XLSB directly
This is the single biggest misconception about the format. Google Sheets cannot import an XLSB file as-is. If you upload an XLSB to Google Drive and try Open with → Google Sheets, the import will fail or produce an unusable file. To get an XLSB into Sheets you must first convert it to XLSX in Excel or LibreOffice, then upload that XLSX and open it with Google Sheets. Once it is in XLSX form, our guide on converting between Excel and Google Sheets covers the rest of the workflow.
Excel for the web has no XLSB support
Likewise, Excel for the web (the free browser version) does not support XLSB. Uploading an XLSB to OneDrive and trying to open it in the browser will not work. You need the desktop Excel app, or you convert the file to XLSX first and then open that XLSX in Excel for the web.
How to convert XLSB to XLSX
Converting is simple in any app that can open the file:
- Open the XLSB file in Excel (or LibreOffice Calc).
- Go to File → Save As (on Mac, File → Save a Copy).
- Change the file type / format to Excel Workbook (.xlsx), or to Excel Macro-Enabled Workbook (.xlsm) if the workbook contains macros you want to keep.
- Pick a location and click Save.
A few trade-offs to keep in mind:
- Choose XLSM, not XLSX, if there are macros. Saving a macro-containing workbook as plain XLSX strips out all the VBA code.
- The XLSX file will likely be larger and may open and save more slowly than the original XLSB, particularly for big workbooks.
- The conversion is non-destructive — Save As creates a new file, so your original XLSB stays intact. If you simply want a backup before experimenting, see how to make a copy of an Excel workbook.
XLSB vs XLSX: which should you use?
| Feature | XLSB (Excel Binary Workbook) | XLSX (Excel Workbook) |
|---|---|---|
| Internal format | Binary | XML in a ZIP container |
| File size | Smaller | Larger |
| Open / save speed | Faster (helps with big files) | Slower on large workbooks |
| Stores macros | Yes | No (use XLSM instead) |
| Opens in Excel desktop | Yes | Yes |
| Opens in Excel for the web | No | Yes |
| Opens in Google Sheets | No (convert first) | Yes |
| Read by Power Query / many add-ins & tools | Often no | Yes |
| Ease of recovery if corrupted | Harder | Easier |
Use XLSB when the workbook is large or slow, calculation-heavy, contains macros, and stays within Excel desktop — it is one of the most effective ways to speed up a slow Excel workbook.
Use XLSX when you need to share the file widely, open it in Google Sheets or Excel for the web, pull it into Power Query or another tool, or simply want the safest, most universally readable format. For routine sharing and storage, XLSX is the better default — more on sensible defaults in our guide to opening older XLS files.
Troubleshooting: when an XLSB file won’t open
“The file format or file extension is not valid.” This usually means the file is not actually a valid XLSB, was renamed from another format, or was damaged in transit. Try opening it in LibreOffice Calc, request a fresh copy, or in Excel use File → Open → Open and Repair.
Excel says the file may be unsafe or blocks it. Files downloaded from the internet or email open in Protected View. Click Enable Editing if you trust the source. If the workbook is also macro-enabled and the macros are blocked, follow how to unblock macros in Excel.
Macros do not run after opening. XLSB keeps macros, but they will still be blocked by Excel’s default security settings until you enable them — and they will be removed entirely if the file was ever resaved as plain XLSX.
Another tool (Power Query, an importer, an add-in) can’t read the file. Many connectors and add-ins simply do not support binary workbooks. Convert the file to XLSX (or export to CSV) and import that instead.
The file opens blank, corrupted, or won’t recover. Binary files are harder to recover than XLSX. Try Open and Repair, open it in LibreOffice as a second opinion, or check whether an earlier version exists — see how to recover an unsaved Excel file for recovery options.
Frequently Asked Questions
How do I open an XLSB file?
Double-click it on a computer with Microsoft Excel installed, or open Excel and choose File → Open and browse to the file. This works the same on Windows and Mac. Without Excel, install free LibreOffice Calc and open it there.
What is an XLSB file?
An XLSB file is an Excel Binary Workbook — a spreadsheet saved by Excel 2007 or later in a binary format instead of the XML-based XLSX format. It is typically smaller and faster to open, and it can store macros, but fewer programs can read it.
Can I open an XLSB file in Google Sheets?
Not directly. Google Sheets cannot import XLSB files. First open the XLSB in Excel or LibreOffice, save it as XLSX, then upload that XLSX to Google Drive and open it with Google Sheets.
How do I convert an XLSB file to XLSX?
Open the file in Excel, choose File → Save As (or Save a Copy on Mac), set the format to Excel Workbook (.xlsx), and save. If the workbook contains macros you want to keep, save it as Excel Macro-Enabled Workbook (.xlsm) instead.
Why won’t my XLSB file open?
Common causes are a damaged or mislabeled file, opening it in a program that doesn’t support XLSB (such as Google Sheets or Excel for the web), or Excel’s Protected View blocking it. Try Excel’s Open and Repair, open it in LibreOffice Calc, or convert a working copy to XLSX.
Is XLSB better than XLSX?
It depends on your goal. XLSB is better for large, macro-heavy workbooks used only in Excel desktop because it is smaller and faster. XLSX is better for sharing, online editing, and importing into other tools, since far more software can read it.
