Advantages of .xlsb Excel Binary Workbook Format


A lot of users are unaware of the many benefits and advantages of .xlsb Excel Binary Workbook Format.

Excel Binary Workbook files store information in binary format instead of the XML format like with most other Excel files. Since XLSB files are binary, they can be read from and written to much faster, making them extremely useful for very large spreadsheets. This also implies that with .xlsb files calculations will be faster and workbooks much smaller.

.xlsx loads 4 times longer than .xlsb and saves 2 times slower and has 1.5 times a bigger file. Reportedly a user from leading forums Stackoverflow tested this on a generated worksheet with 10’000 rows * 1’000 columns = 10’000’000 (10^7) cells of simple chained =…+1 formulas:

.xlsx .xlsb
loading time ║ 165s │ 43s
saving time ║ 115s │ 61s
file size    ║ 91 MB │ 65 MB

In addition from a security point of view, since data is in binary format and not in XML, .xlsb files will display unreadable contents if a user tries to change the extension of the file to .zip.

Other advantages of .xlsb file format include:

– Saving in binary allows formulas to be saved properly if they are longer than the 8192 character limit
– Macros, VBA code is fully supported

Disadvantages and downsides of .xlsb files:

– No Ribbon modification allowed for XLSB formats. You must convert back to XLSM, make your Ribbon changes, and then back to XLSB
– A potential lack of interoperability with OpenOffice
– Not compatible with Excel 2003 and previous versions
– Compatibility in using the data with software that wants XML instead of binary (web server for instance). If you link a lot of systems together, this may cause a problem with one of the layers, as XML was developed specifically for this purpose.
Our award-winning security software XLSafe CORE fully supports the .xlsb extension and we highly recommend this for very large and complex files.