What is the difference between xls vs xlsx file format?
What means the last X in an XLSX file format?
XML is a computer language. It means eXtensible Markup Language. In fact, it's a language where all the data are ordered and zipped.
It's not easy to understand for humans but for a computer when data are ordered, it's easier to store and read. So the XLSX files access faster to data. 👍
Reduce the size of your Excel files
XML is a language that compresses automatically the data. So when you save your XLS file to XLSX, the size of your document will be reduced.
For instance, in the following screenshot, the same file has been saved with XLS and XLSX extensions. The XLSX file is 3 times smaller than the XLS file with the same data 😲😲😲
A 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.
Protection against macros
- .xlsX workbooks have no macro
- .xlsM, workbooks have macros
We have seen that the last x of an xlsx file indicates that the file is compressed and respects the XML standard. The M, of an xlsm file, indicates the file contains macros
A macro is a program written by an end-user to provide automation (opening files, data comparison, data aggregation across multiple sheets, ...) but also a program may cause malfunctions. In addition, a macro can run directly when you open an Excel file, without prompting the user.
So with an XLSX file, you can be sure your file has NO macro (and NO virus).
With an xls file, you don't know whether your workbook contains macros or not 😱😱😱
Work with Tables
The Table tool is very powerful to work with your data in your workbook. Tables are very useful to create dynamic functions, change the design quickly or select easily rows or columns.
But Tables are only available with xlsx files. If you save your work to xls, your Tables will be destroyed and unusable.