What it actually is
NetQuake.io runs Quake in the browser with no download. The free shareware episode is included, you can unlock the full game with files from your own copy, and multiplayer is supported. It is the cleanest example of what the post promised.
The legitimate way to play
Free shareware episode; full game requires your own copy (Quake is sold on Steam and GOG).
If Quake won't load
- Give the first load time. Quake downloads its engine and data before the first frame, and a cut-off download often looks like a frozen black screen. Reload once on a stable connection before trying anything else.
- Click inside the game window before pressing keys. Browser games only receive keyboard and mouse input once the page has focus, and most need a click to capture the mouse.
- If the screen stays black, run our browser check. A missing WebGL 2 result usually means an outdated browser or a graphics driver the browser has blocked.
Chromebook, phone and tablet
On a Chromebook, Quake should start in Chrome as long as the browser check shows WebAssembly and WebGL 2. Low-end Chromebooks may need lower graphics settings, and managed school devices can block sites or downloads entirely; follow your school's rules. It is built for keyboard and mouse, so a phone or tablet is not a realistic way to play it.
Play something similar right now
Questions
Is Quake free in the browser?
The shareware episode is free. The rest needs your own copy.
Is there multiplayer?
Yes, NetQuake.io supports multiplayer.
Is this connected to Radiant Optimizer?
No. Radiant Optimizer is Windows tuning software. This title was simply included in a viral post by its X account.