.XLSB File Extension
File TypeExcel Binary Spreadsheet
This file is saved in a binary format, which requires a specific program to read its contents.
What is an XLSB file?
An XLSB file is a spreadsheet file created by Microsoft Excel, a program used to create and edit spreadsheets. It contains a spreadsheet of cells arranged by a grid of rows and columns, as well as charts, macros, and formatting. XLSB files are saved in a binary format.
XLSB files differ from standard Open XML format (.XLSX) spreadsheets since they store the spreadsheet using a binary format (BIFF12). You will most likely see and use the XLSX file more often because it is compress to save space and is easier to share with other users. XLSB files are not compressed, making them larger in size than XLSX files. However, XLSB files may perform more efficiently within Excel because they are saved in the larger binary format.
NOTE: XLSB files may be opened by Excel 2007 or later, or by earlier versions of Excel with Open XML support.