About Doom 3
Doom 3 is a first-person shooter and survival horror game developed by id Software and published by Activision. It came out for Windows on August 3, 2004, then for Linux later that year, for Mac OS X in 2005 through Aspyr, and for the Xbox in April 2005. It was the first game on the id Tech 4 engine and sold more than 3.5 million copies, id’s best result up to then.
The game is set in 2145 on Mars, where teleportation experiments at the Union Aerospace Corporation base open a gateway to Hell. You play a space marine fighting zombified staff and demons through the base. Darkness is the main source of fear: in the original release you hold either a weapon or a flashlight, not both. id Software released the engine’s source code under the GPL in November 2011, while the game’s art and sound stay under its license. For where the series started, see Doom.
How it runs in your browser
D3wasm is an experimental port of id Tech 4 to WebAssembly by Gabriel Cuvillier of Continuation Labs. It’s built from dhewm3, a source port of the GPL Doom 3 code, so it’s not an emulator. Pressing Play opens his online demonstration in a new tab.
This is the Doom 3 demo, not the full game. Cuvillier says the demo’s license allows non-commercial redistribution. He says he asked Bethesda and ZeniMax for clearer permission but got no reply, and he points anyone who enjoys the demo to the full game.
According to the project page, you need a browser with WebAssembly, WebGL and IndexedDB, a good CPU and about 850 MB of free memory. About 400 MB of data downloads once and is cached: roughly 15 MB to reach the main menu, then the rest loads in the background. You can save, and saves stay in your browser, but private browsing blocks this storage.
On 3 November 2026, in desktop Chrome, it loaded to the Doom 3 main menu, with New Game, Load Game, Multiplayer and Options. We didn’t start a game. The main data file alone is about 385 MB, so on a slow connection the first level can take a while to load.
Controls and devices
The default keys are WASD and can be changed in the game. The Home key replaces Esc, opening the main menu or skipping a cutscene, and Insert opens the console. The resolution starts at 960 by 640, and Alt+Enter restarts the video. The game is very dark, and the developer notes that the in-game brightness setting doesn’t work, so turn up your screen instead. He says phones can load it but it isn’t playable there, with no touch controls.
Who it’s for
The demo suits anyone curious about Doom 3’s slow, dark take on the series, and anyone who wants to see a 2004 engine that strained many PCs of its day running in a tab. For a faster id shooter in a browser, try Quake.
Is Doom 3 Free, Safe and Official?
Is this the full version of Doom 3?
No. It’s the Doom 3 demo that id Software made free to pass around, running on a fan port of the engine. The full game is sold separately.
Can I play Doom 3 free in my browser?
Yes, the demo. D3wasm runs it in a browser tab with no install and no account. The developer says the first visit downloads about 400 MB of game data, which the browser keeps for later visits.
Can I save my progress in the Doom 3 browser demo?
Yes. The developer says saved games and settings are stored in your browser’s IndexedDB storage, which doesn’t work in private browsing windows.
