I'm pretty sure chess.com uses Glicko still, but I'm not certain on which version. Details on the chess.com rating system used to exist in your profile via chess.com "stats" - things like Glicko RD (k-factor), but the newest update made this "hidden."
I don't think it changed any, but it is no longer viewable. At least this is the way I understand it.
I was wondering what Rating system is used on chess.com these days. Rating-Deviation used to be visible iirc, but it isn't anymore (or it is really well hidden). Is this because we aren't using Glicko anymore (but what would be used instead? a proprietary algorithm? Elo?!) or does it still exist and is justhidden?
And if we are using Glicko, does anyone know which version of Glicko we are using? The lichess FAQ notes that chesscom uses Glicko-1, but I can't find a direct source on that, so it might just be outdated? Just based on "feel", I'd expect it to be Glicko-1 rather than Glicko-2, but that is only if it is Glicko at all.
Not sure if this is the correct subsection of the forum, but it seemed to be closest.