Browser Games
The legal versions from the list of 24: open-source engines running free game data, or game files you already own. Games you've opened once keep working offline in this browser.
Play
Quake 1
The real game: WebQuake engine (GPL port of id's source) + the free shareware episode, which id allows to be passed around for free.
Fully legalOpenArena (Quake 3)
ioquake3 (GPL Quake 3 engine), which I compiled for the browser, running OpenArena: a free, open game made to replace Quake 3's paid content. Offline against bots (Single Player → Skirmish), or jump straight in: quick deathmatch.
The first load downloads about 400 MB. After that it's cached in your browser.
Fully legalHalf-Life, Opposing Force, Blue Shift
Open-source Xash3D FWGS engine + hlsdk-portable game code, which I compiled for the browser, running the game files from your own copy: the page asks you to choose your Half-Life folder once. Your game files stay on your computer.
Legal with your copyCS Surf
Surfd.net is an original game, not open source. Surf is a game mode, so this is my own version with Source-style air strafing.
Original, legalAll 24, checked
| Game (site) | Verdict | Why |
|---|---|---|
| BO1 Zombies vel.gg/bo1z | No | Unofficial port of Activision's actual game: their maps, models and sounds. |
| Moon | No | Same Call of Duty port (Black Ops map). |
| Kino der Toten kino-der-toten.pages.dev | No | Call of Duty assets. The link now redirects to an unrelated domain, so avoid it. |
| BO3 Cheese Cube cheese-cube.pages.dev | No | Call of Duty custom map. The link now redirects to the same unrelated domain, so avoid it. |
| Black Ops 2 vibeslops.luckeysystems.com | No | CoD browser port, already taken down by an Activision DMCA. |
| Modern Warfare 2 ovz-game-production… | Play there | Actually an original game ("Contemporary Conflict"), not MW2. Not open source, so there's nothing to port, but it's fine to play on its site. |
| Skate 3 skate.aaddpp.lol | No | Streams data from a converted copy of EA's console game. Its donate link goes to a crypto token page. |
| Skate Rust global-terror.net | ? | Now a merch/video storefront. No game to be found. |
| CS Surf surfd.net | Yes | Original free game. My own surf version is above. |
| Halo CE mitchellhynes.com/halo | No | Built on a decompilation of Microsoft's code and needs an Xbox disc image you'd have to own. Taken down more than once. |
| Halo CE mobile hcemobile.com | No | Same decompilation, same disc-image requirement. |
| PES 6 pes6.optijuegos.net | No | Konami's PSP game recompiled with the original data. |
| GTA 5 web.archive.org | No | Rockstar's game. Nothing open about it. |
| GTA Vice City joncodeofficial.github.io | No | Based on the reVC decompilation plus Rockstar data. Take-Two filed DMCAs against these ports. |
| Simpsons: Hit & Run shar-wasm… | No | Built on the game's leaked (stolen) source code. |
| Quake 1 q1.pieter.com | Yes | GPL engine + free shareware episode. Set up above. |
| Quake 2 q2.pieter.com | Own copy | Engine is GPL, but the game data is paid and you don't own it. Easy to add if you buy it (cheap on Steam). |
| Quake 3 q3.pieter.com | Yes | Engine is GPL, data is paid. That site actually runs OpenArena, which is fully free. Set up above. |
| Return to Castle Wolfenstein rtcw.pieter.com | Own copy | iortcw engine is GPL, but the ~380 MB of game data is paid and you don't own it. |
| "Unreal Tournament" ut.pieter.com | Free | That site is really Urban Terror, a free game on a Quake 3 engine fork. Free to download and play on desktop at urbanterror.info. |
| Half Life pixelsuft.github.io/hl | Own copy | Xash3D FWGS (open engine) needs Valve's files. You own Half-Life, so it's set up above with your files. |
| Half Life / CS 1.6 x8BitRain webXash | Own copy | Half-Life as above. CS 1.6 offline needs Valve's closed server code or a reverse-engineered copy. You own CS 1.6 on Steam, so play it there. |
| Diablo johnimril.github.io | Grey | DevilutionX is built from a decompilation of Blizzard's code. Skipped as a grey area. |
| Hedgewars webwars.link | Free | Fully open source (GPL), but no working browser build exists (the old one died in 2013). Free desktop download at hedgewars.org. |
Extra: my own original FPS remakes
Built before the switch to "legal versions only". All code is mine, with no copied assets. They play like the originals but contain nothing from them.