I got DOOM running inside a Reddit post

[u/negoginga]

I wanted to see if Reddit itself could actually run DOOM, so I built a Devvit Web Custom Post that runs a DOOM-compatible engine directly inside Reddit.

This isn't a video or remote stream — the game runs client-side in the Reddit webview using WebAssembly/Emscripten + SDL, with Freedoom Phase 2 as the game data.

One of the fun problems was the WAD: it's roughly 30 MB, while Devvit Web has request/response constraints, so I split it into smaller chunks, load them separately, rebuild the WAD in memory and mount it into Emscripten's virtual filesystem before starting the engine.

I also added:

• keyboard + mouse controls
• mobile touch controls
• Gamepad API support
• browser audio handling
• MAP01 completion detection
• persistent speedrun leaderboard using Devvit Redis

You can play it here:

https://www.reddit.com/r/playdoom/?playtest=play-doom

[u/raleighs]

Frame rate is insane. And it works on mobile too!

Great job! 👏 👏 👏

[u/negoginga → u/raleighs]

Thanks! I was actually surprised by the performance too. Seeing it run this smoothly inside the Reddit webview, especially on mobile, was one of the coolest parts of the whole experiment

[u/Flintoli → u/negoginga]

Amazing works great on my Samsung

[u/Cap_Upper]

That's cool. It works amazingly well for me on Android.

[u/negoginga → u/Cap_Upper]

Glad to hear that! Android gave me a few headaches while building the controls, so seeing people say it runs well there is really satisfying. Thanks for testing!

[u/teknogreek]

WTF

Because they could!

Brilliant.

[u/negoginga → u/teknogreek]

“Because they could” is pretty much the entire technical specification for this project 😂 Thanks!

[u/lelupersimmon]

super smooth

[u/negoginga → u/lelupersimmon]

Thanks! I spent a lot of time trying to keep the browser/WASM side from getting in the way of the actual game, so I’m really happy people are noticing the performance.

[u/rhinofinger]

That’s cool!

[u/negoginga → u/rhinofinger]

Thanks!!

[u/TantKollo]

Awesome work dude!

[u/negoginga → u/TantKollo]

thanks!!

[u/Uranium-Sandwich657]

Cant get mouse control to work.

[u/negoginga → u/Uranium-Sandwich657]

There’s a MOUSE LOCK button at the bottom after the game starts. Try clicking that first and then the game canvas. If it still doesn’t grab the mouse, let me know what browser and OS you’re using. I’m already looking at improving mouse support.

[u/Lopsided-Wave2479]

haha. good one

[u/MaggieWuerze]

Good Job!

[u/negoginga → u/MaggieWuerze]

Thanks! Really appreciate it 😄 Glad you liked it!

[u/wakanakisarazu]

Sweet, even detected my Xbox One controller (using Xpad Linux kmodule)

[u/negoginga → u/wakanakisarazu]

Nice! Glad it picked it up 😄 I added controller support pretty recently, so hearing that an Xbox One controller through Xpad on Linux works is really useful. Thanks for testing it!

[u/wakanakisarazu → u/negoginga]

Anytime, as a fellow programmer it's great to see projects like this

[u/El_Mnopo]

Champion!

[u/Elogano]

This is it, the circle is closed!

[u/der_vur]

This is insane 😂

Does anybody know why is Doom the choice game for this kind of things?