Grand Theft Auto: San Andreas can now run inside a web browser with no installation required. The work is the result of a solo developer who built an open-source engine called OpenSA that streams the game's world, vehicles, physics and lighting straight into a browser tab. The catch is how it was made. Most of the code came from AI.
First, let's start with what OpenSA actually is.It is not a Grand Theft Auto port and definitely not a clone. It is a from-scratch game engine compatible with RenderWare, the format the original game was built on and it distributes none of Rockstar Games' assets. To run anything, you supply your own legally owned copy of GTA: San Andreas or a compatible total-conversion mod. OpenSA is merely the engine. You still need to bring the official copy of the game.
The build story is just as interesting as the actual mod itself. Serhii Aleksandrov, a full-stack web developer and former 2000s GTA modder, put the first public demo together in roughly three weeks, and by his own account leaned on Anthropic's Claude Code as a coding partner for a large majority of the work. A recent version then ripped out its original off-the-shelf graphics library for a custom WebGPU engine, pushing city scenes from a rough 16 to 24 frames per second up to a locked 120.
What OpenSA is and what it is not
Point | The reality |
|---|---|
What it is | A from-scratch browser engine compatible with RenderWare |
What it is not | Not a port, not a clone, not a copy of the game |
The assets | You supply your own legal San Andreas files |
The build | Made largely with AI, in about three weeks |
The tech | A custom WebGPU engine hitting a locked 120 fps |
OpenSA runs your own copy of San Andreas, it does not hand you the game.
The resulting mod is capable of running the entirety of Los Santos with proper streaming, day-night lighting, driveable cars with damage, character controls and a pile of small touches like tire smoke, skid marks and license plates. For a solo hobby project, in a browser, that is a lot. The creator is clear that it is an experimental, educational fan project, with GTA and its trademarks belonging to Rockstar and Take-Two Interactive.
At the risk of making ourselves sound like a broken record, this fits a run we have been tracked all year of classic GTA turning up where it was never meant to run, mostly because of AI, from Grand Theft Auto III on the Wii to Grand Theft Auto: Vice City on a GameCube to Grand Theft Auto V on an iPhone and a developer who who vibe-coded a clone of Grand Theft Auto VI but ultimately decided to pursue an entirely different project. A browser is just the latest unexpected home albeit one that has already welcomed GTA: Vice City before.
The legal ground is the usual gray area for this scene. OpenSA ships no Rockstar code or assets and makes you bring your own game, which is the standard workaround these projects lean on to survive. Unfortunately, Rockstar's new mod guidelines bar running its games on platforms where they were never officially released. A browser is squarely one of those. Where a from-scratch, asset-free engine sits against that line is a question we don't have an answer to yet and one Rockstar has not spoken to here.
For now, OpenSA is a genuinely impressive tech demo that says as much about how games get built as about as GTA: San Andreas itself. A twenty-year-old game in a browser tab, its engine rewritten by one person and an AI in a matter of weeks.
Whatever happens to this specific project, that is the part worth remembering long after GTA 6 arrives.