Why is XLSB smaller than XLSX?

Why are Excel binary files smaller?

An XLSB file is a Excel Binary Workbook file format. Binary files are usually read and written to much quicker and are more smaller than non-binary files. This is because binary files are a raw dump (basically 1's and 0's) of memory.

Does XLSB reduce file size?

Advantages of XLSB format: It reduces the Excel file size. This can be helpful when you have large files and you want to share it over email. You can quickly reduce the size by saving it in XLSB. XLSB files tend to open and save faster than XML file.

Why is XLSX so large?

This is what makes the file so large: Excel is picking up a lot of empty cells and thinks there's data in them, which then it tries to save into the XLSX file on disk, and because it needs to keep references to all those hundreds or thousands of cells, the file size gets overblown.

Why is XLS bigger than XLSX?

Bigger range of cells. In an XLS workbook, the row limit is 65,536 (216) and 256 columns (28) which corresponds to column IV. Now with xlsx workbooks (and xlsm), limits are 1,048,576 rows (220) and 16,384 columns (214) or the column XFD.