The average favicon network request takes 130ms, at least from our speedy cloud instance.
I would have guessed most favicons are ICO, but no:
The vast majority of the favicons offered up by websites are PNG. 71.6% of <link rel=”icon”> images are PNG.
21.1% of /favicon.ico files are secretly PNGs
One of the reasons that file extensions, to browsers, are rather meaningless. It’s all about that content-type.
Also, they question the accuracy of the method, but the dominant color in the analysis so far is purple. I hope it ends up true as it kinda makes sense. Unless you’re offering different favicons for dark mode, using white or black seems too dangerous these days.