Can I use… WebM video format
WebM video format. Multimedia format designed to provide a royalty-free, high-quality open video compression format for use with HTML5 video. WebM supports the video codec VP8 and VP9.
Global 79.04% + 18.82% = 97.86%
How to generate a cross browser and responsive favicon
The favicon is supposed to be a set of 16×16, 32×32 and 48×48 pictures in ICO format. ICO format is different than PNG. Non-square pictures are not supported.
To generate the favicon, for many reasons explained below, I advise you to use this favicon generator. Full disclosure: I’m the author of this site.