You can now search for file properties such as file size and and file type on Commons. This includes file media type, MIME type, size, width, height, resolution, and bit depth.
A few quick examples:
* A search for 'shark' videos [0]
* A search for 'flower' where the files are 16 bit [1]
* A search for 'stars' where the files are PDFs [2]
Please see the documentation for more information. [3]