MAT-files are binary MATLAB® format files that store workspace variables.
To see the variables in a MAT-file before loading the file into your workspace, click the file name in the Current Folder browser. Information about the variables appears in the Details Panel.
Alternatively, use the command whos -file filename. This function returns the name, dimensions, size, and class of all variables in the specified MAT-file.
For example, view the contents of the example file durer.mat:
whos -file durer.mat
Name Size Bytes Class Attributes X 648x509 2638656 double caption 2x28 112 char map 128x3 3072 double
The byte counts represent the number of bytes that the data occupies when loaded into the MATLAB workspace. Compressed data uses fewer bytes in a file than in the workspace. In Version 7 or higher MAT-files, MATLAB compresses data. For more information, see MAT-File Versions.