Halo is now playable in a web browser with multiplayer support
Anyone who’s been using Xbox lately has probably noticed the bizarre scene surrounding modified video games. Clips are circulating of Call of Duty operators performing kickflips and other tricks from Skate, people playing Black Ops 1’s Zombies mode in Skyrim, and Miles Morales swinging through Gotham. Someone even managed to get the Xbox version of Halo: Combat Evolved running in a web browser with multiplayer and split-screen support.
Software developer Mitchell Hynes has brought Halo to web browsers. As he posted on X, this version of the game offers split-screen co-op and a multiplayer mode for up to 128 players. He is currently running a website on Cloudflare to host the port – this is the original Xbox version of Combat Evolved, not the controversial PC version from Gearbox – and shared the link to the website in a reply to his original post. According to Hynes, 20,000 people played the browser version in the first five hours.
What made the unofficial Halo port possible?
The simple explanation for the sudden proliferation of browser ports and wild mashups on social media is a new version of Claude that significantly simplifies their creation. Thanks to AI, modders can decompile games much faster (a process that grants access to the source code), making it easier to bring them to web browsers and other platforms (mostly also with the help of AI).
Halo: Combat Evolved was recently decompiled for the first time, and although the associated GitHub page does not confirm whether AI was involved in this process, there are numerous references to Claude in the project’s Discord channel.
Regarding the game mashups appearing on social media, many LLMs use tools like Claude Opus 5.5 with a special universal modding plugin. “With Claude, you can modify any game. Skills, tools, and the fal MCP allow Claude Code to modify almost any PC game you own: reconnaissance, reverse engineering, fal-generated graphics/3D/audio, in-game testing, and presentation videos,” reads the tool’s description.
This situation naturally presents numerous moral, legal, and technical pitfalls. As experts have already noted, these decompilations and mods are more likely to contain errors due to their creation using vibe coding. Subsequently, X user Funky90sLion compiled a list of existing, human-maintained decompilation projects.
Regarding the legal aspects, many publishers are likely less than thrilled that their games are being used in such mashups, even if the modders legally acquired the original games. Furthermore, using Claude to create these mods raises the typical environmental and ethical concerns associated with this technology. And while these mods make for entertaining social media clips, they are more like technical gimmicks compared to the more immersive gameplay experience of the original games. As with all cases where AI is used for “creative” purposes, the end result is invariably a remix of existing works, which were usually included in the AI’s dataset without the copyright holder’s permission.
In the case of the web browser version of Halo: Combat Evolved, it is expected that Microsoft will take action against the unofficial port, which is still playable at the time of release. Xbox had previously released Halo: Combat Evolved Anniversary, a remastered version of the original game, and subsequently ported it to PC via Halo: The Master Chief Collection. Earlier this year, Halo: Campaign Evolved, a complete remake of the original game’s story mode with additional missions, was also released.
