Yeah there are a couple versions uploaded and they are pretty bad

I did find this notice on one of the versions, unfortunately I think there is just something about Quake that makes it hard to emulate in browsers at the moment :(

Please note: This Web-Based emulation of Quake is extremely slow; the game is not playable at this speed (although manipulating the settings for a lower resolution and reduced complexity will increase speed nominally). This item is included for historical reasons only and will hopefully one day be more playable