Minecraft: Java Edition 26.3Written in Rust
Horizon: The game you know,rebuilt in Rust.
The Minecraft: Java Edition 26.3 client and its game logic, rewritten in Rust and checked against the vanilla game by differential harnesses.
Benchmarks
3× the frame rate.
Average frames per second in vanilla 26.3 with no mods installed.
Drag the standard launcher bar to try your own frame rate. Results vary with hardware.
What it is
Same inputs, identical outputs.
Horizon, sometimes called Minecraft Rust Edition, rebuilds Minecraft: Java Edition 26.3 in Rust, one subsystem at a time, and holds every piece to the same inputs as the vanilla game until the outputs are identical.
Visit contributors(opens in a new tab)
Your own copy
Install Java Edition with the official launcher and play 26.3 once. Horizon builds its resources from those files on your machine, and never downloads or shares game files.
Native on three platforms
Linux, macOS on Apple Silicon or Intel, and Windows on x64 or ARM. Worlds come from a Rust port of the vanilla generators, drawn with vanilla's block models, lighting, sky and fog.
Open source
Horizon's code is MIT. It contains no Minecraft code, assets or data; those belong to Mojang and Microsoft under the Minecraft EULA.
Your Minecraft
Server, 24/7 Online.
Get your server now in under ~60 seconds!
Community
Built in the open.
Every change lands on GitHub in public. Come ask questions, report bugs or send a pull request.
- DiscordQuestions, bug reports and screenshots.
- SponsorSponsors on GitHub fund the next release.
- SourceIssues and pull requests are welcome.
- How it's builtWho writes it, how changes are checked, why it's safe to run.
Do you make 3D models? Horizon is looking for 3D artists.
Drawn byHorizon
The same game you love, 6× faster.
Every frame here was rendered by Horizon, with vanilla's block models, lighting, sky and fog.
Contributors
Built by 294 people.
Everyone with commits in horizon-rust/horizon, most commits first, and the people behind this site.
ludovic11112,199 commits
Anthony SWebsite Developerkacpherek1,523 commits
rdbtCVS1,521 commits
levzzz51541,201 commits
MSedgeMC1,112 commits
281
differential harnesses when we started: each drives the same inputs through Horizon and through the vanilla client and server, and compares what comes out.
Where the project started.
Below is the project's first audit of each subsystem: what its harnesses compared then, and how much of it they covered. It is not a parity claim: players still find differences, and parity work on 26.3 continues, redstone first.
Audited players still find differences: the open reports(opens in a new tab)
01Window, input and game loopPassed its harnesses
Passed its harnesses
The game loop, options, camera, auto-jump, toggle sprint/sneak, local input and the frame limiter match vanilla.
02Assets and resourcesPassed its harnesses
Passed its harnesses
Item models match vanilla over 196,290 stacks and the client draws every item through them; the resource pack screen matches vanilla's drawing over 3,000 sessions of clicks, scrolling and searching, its incompatibility confirmation included.
03Network protocol and multiplayerPassed its harnesses
Passed its harnesses
Joins vanilla servers; the dedicated server (--dedicated) matches vanilla's files, status ping, login, configuration, play, chunks, chat, recipes, advancements and command tree, a client built from vanilla's packet code joins it, Horizon joins a vanilla server, and LAN discovery matches over 462 cases (offline mode only).
04Chunk storage and palettesPassed its harnesses
Passed its harnesses
Client and saves share paletted containers, identical to vanilla over 266 scenarios.
05Section meshingPassed its harnesses
Passed its harnesses
112 scenes and over a million quads identical to vanilla.
06RenderingPassed its harnesses
Passed its harnesses
Entity models, block entity renderers (407 cases, End portals, gateways and the loom's banner preview included) and their animations (296 cases, End gateway beams included), the HUD overlays (2,200 states), the recipe book (600 states), the player list, subtitles and the world border match vanilla.
07LightingPassed its harnesses
Passed its harnesses
Saved and relit light matches vanilla, slabs and stairs included.
08World generationPassed its harnesses
Passed its harnesses
2,352 whole chunks over 225 structure sites, in all three dimensions, identical to vanilla.
09Region files and savesPassed its harnesses
Passed its harnesses
Saves round-trip with vanilla, and worlds from 1.8 to 26.2 upgrade as vanilla's DataFixers do, superflat worlds included; old options.txt and hotbar.nbt files are upgraded too.
10Entities and physicsPassed its harnesses
Passed its harnesses
Attributes, dimensions, death loot, spawn rules, natural spawning (15,500 cases), raids and patrols (1,900 cases), spawned mobs' gear, enchantments and state (finalizeSpawn, 24,000 cases) and mob AI (92 scenarios: villager breeding and gossip, the warden, ghastlings and copper golems included) match vanilla.
11Interaction and inventoryPassed its harnesses
Passed its harnesses
Menu clicks match over 8,000 click sequences, the loom and the crafter included; recipe book placement (6,000 cases), its buttons (1,200), the saved book (1,500) and the loom and crafter screens (1,600) match vanilla.
12Menus, HUD and chatPassed its harnesses
Passed its harnesses
Every command runs as vanilla (758 commands over 39,685 parsed inputs), scoreboards and teams match (81,000 operations), the player list matches over 872,000 draw calls with heads drawn from players' skins (authlib's textures, SkinManager's lookup, legacy skin conversion), and the chat matches focused and scrolled; the resource pack screen (selection over 4,000 cases, drawing and its incompatibility confirmation over 3,000 sessions) and the chat input with its command suggestions, usage lines, Tab completion and history (3,000 sessions on vanilla's client command tree) match vanilla.
13AudioPassed its harnesses
Passed its harnesses
The sound engine, sound events, music, situational music, ambience and subtitles match vanilla.
14Block behaviours and tickingPassed its harnesses
Passed its harnesses
Block updates, random ticks, redstone, dispensers (6,000 cases), crafters (4,000 crafts), block entity removal (containers spill, 4,000 cases), copper golem chest sorting and the sculk family (435 scenarios: shrieker warnings and warden summoning included) match vanilla.
Each subsystem scored
- 0 absent
- 0.25 started
- 0.5 playable, major features missing
- 0.75 mostly complete
- 1 its harnesses cover it and pass