How to open .XLSB files on iOS
To open .XLSB files on iOS, if you have access to Microsoft Excel on a desktop (Office 2007 or later), open the .xlsb there; if a mobile app cannot open it reliably, convert it in Excel to .xlsx for easier sharing.
Step-by-step instructions
- If you have access to Microsoft Excel on a desktop (Office 2007 or later), open the .xlsb there; if a mobile app cannot open it reliably, convert it in Excel to .xlsx for easier sharing.
Common issues
Workbook won’t open or shows as an unsupported format
.xlsb is the Excel Binary Workbook (BIFF12) format and is supported in Excel, but older Excel versions or non-Excel tools may not fully support it.
- Open the file in Microsoft Excel (Office 2007 or later).
- If you need to use another program, open it in Excel first and save a copy as .xlsx.
File is large or slow; need a smaller version for sharing
Large workbooks can be bulky in some formats. Microsoft explicitly suggests saving as .xlsb as one approach to reduce Excel file size.
- In Excel, use File > Save As.
- Choose “Excel Binary Workbook (*.xlsb)” to create a smaller copy.
Automation/macro safety concerns
.xlsb files are workbooks and can be used in environments where macro-enabled content exists; users may treat them similarly to other Excel files when assessing trust and origin.
- Only open .xlsb files from trusted sources, especially if you were not expecting the workbook.
- If you must share with others who have stricter policies, consider saving an .xlsx copy without any active content you don’t intend to distribute.
Security note
.xlsb is a binary Excel workbook format; treat unexpected .xlsb attachments as potentially risky content because spreadsheet files can be used as a delivery vehicle in social engineering scenarios.