We are testing to see if a GIF image will be preferred as an image format.
Does Google prefer a GIF over a PNG?
Test Downloads
Transcription Below
Derek Booth has run this test.
He has run several of these image tests.
The foundation of all these image file test was Google always says that the nicest and unique are the best. So there are some files that are actually better – like PNG is the better file than JPEG, for example.
The bottom line is, there is no benefit, we cannot see any benefit between the different file names in terms of ranking when doing your images.