Install and first launch

What you need

• Minecraft: Java Edition 26.3, played once. Install it with the official Minecraft launcher (or Prism Launcher, MultiMC, the Modrinth App, ATLauncher or GDLauncher) and start 26.3 once, so it downloads its files. Horizon reads them from there and never copies them anywhere else.
• Java 25, a JDK. For example Eclipse Temurin 25. Only the one-time preparation uses it. The game itself needs no Java.
• A computer on the supported list. On Linux and Windows that means a graphics card with Vulkan (or DirectX 12 on Windows).

Download the launcher

Get the newest launcher from the Download button on the home page, which picks the right file for your system, or from the launcher releases on GitHub.

• Linux: download horizon-launcher-linux-x86_64.tar.gz, extract it and run horizon-launcher.
• macOS: download horizon-launcher-macos-arm64.dmg, open it and drag Horizon onto Applications. The first time, macOS says it cannot check the app, because it is not signed with a paid Apple developer account. On macOS 14 and earlier, right-click Horizon, choose Open, then Open again. On macOS 15 and later, open it once, then go to System Settings, Privacy & Security and choose Open Anyway. After that it opens normally.
• Windows: download horizon-launcher-windows-x64.zip, extract it and run horizon-launcher.exe.

Every release also carries SHA256SUMS and a signature, SHA256SUMS.sig, if you want to check your download. The launcher does not check that signature for you yet.

First launch

1. Open the launcher. On the Play page, if it says "No version installed yet", choose Choose a version. On the Versions page, install the newest one. The launcher installs it in its own folder.
2. Back on Play, the launcher says "Not prepared. Horizon needs the files of your own Minecraft 26.3." Choose Prepare. It finds your Minecraft folder by itself in the usual places. If it cannot, it lists where it looked, and Choose… next to the Minecraft folder lets you point it at yours.
3. Wait a few minutes. When it says "Prepared for Minecraft 26.3", choose Play.

The game opens on Horizon's own title screen. Your worlds, options and logs live in the game folder, which is not inside a version's folder, so updating or removing a version never touches them:

• Linux: ~/.local/share/horizon
• macOS: ~/Library/Application Support/horizon
• Windows: %APPDATA%\horizon

No Microsoft sign-in yet. The launcher's Settings page has an Accounts section, but signing in with a Microsoft account does not work for players today. It needs an app registration and an approval from Mojang that the project does not have yet. You do not need an account to play single player.

Updating

• Horizon. The launcher looks for a new release when it starts and every four hours while it is open. With Install new versions automatically on (the default), it installs one and moves you to it if you were on the newest. New releases come out many times a day, and old versions stay installed until you remove them on the Versions page.
• The launcher. It updates itself from its own releases, then shows Restart in its footer.

Stable and beta builds

The launcher installs stable builds by default. In Settings, Beta builds installs new builds the moment they are released, before they have had time to settle. The Versions page shows each version's channel. Releases becoming stable by themselves, six hours after they come out, is coming; until then every release counts as stable.

The Versions page

It lists Horizon's releases, newest first. You can install a version, remove it, or choose which one Play starts. Each release's notes are on the Patch notes page, and on GitHub.

Something went wrong

See Logs, crashes and bug reports.