Crit Launcher FAQ

What is Crit Launcher?

Crit Launcher is a free, open-source Minecraft launcher and client manager. It is built to be fast and simple: it manages your instances, mods and Java versions, and it contains no ads and no telemetry.

Which platforms are supported?

• Windows: supported.
• Linux: supported. Builds are published through the official repository.
• macOS: in development, including Apple Silicon.
• Android and iOS: in development. No mobile version has been released yet, so any mobile app that uses the Crit Launcher name is not ours. Avoid it.

Only download Crit Launcher from the official GitHub repository or from critlauncher.xyz.

Is Crit Launcher open source?

Yes. The whole application, including the build pipeline and the Crit Client integration, is public in our GitHub repository. You can read the code, audit it, and compile it yourself.

Does Crit Launcher cost anything?

No. Crit Launcher is a non-profit community project. It is free, has no ads, and does not bundle any other software.

What is Crit Client?

Crit Client is the optimization client built into the launcher. It is tuned for higher FPS, smoother frame times, lower input latency, and sensible use of your system resources while the game is rendering.

How does Crit Launcher handle mods and shaders?

You can search for, download, update and manage mods, resource packs and shaders from inside the launcher, without opening a file browser. It connects to two sources:

• Modrinth: community optimization mods, Fabric projects and resource packs.
• CurseForge: a large catalog of modpacks, both older and current.

Can I use custom Java arguments?

Yes. Each instance has its own settings where you can add custom Java arguments. That lets you tune garbage collection, set memory allocation with flags such as -Xmx and -Xms, and adjust threading.

Can I host a local server from the launcher?

Yes. Crit Launcher has a built-in local server host. You can start a multiplayer server for your local network from the launcher interface, without setting one up by hand in a terminal.

What is Crit Launcher built with?

• Interface: Electron, so the launcher UI is built with web technologies.
• Native layer: Horizon. The Horizon Loader is written in Rust and handles file operations, integrity checks and game startup.

Do I need to install Java?

No. Crit Launcher manages Java for you. It detects what the selected Minecraft version needs, for example Java 8 for older versions or Java 17 or 21 for newer ones, then downloads, verifies and uses the matching runtime on its own.

Where are my game files stored?

Crit Launcher keeps everything in its own separate crit launcher folder: instance settings, downloaded mods, profiles and cache. This keeps it from clashing with other launchers or an existing .minecraft folder.

Base game files such as assets, indexes and vanilla resources are downloaded from Mojang’s official servers and stored separately from other clients.

How do skins and capes work offline?

In offline singleplayer worlds, Crit Launcher can show your custom skin and cape locally.

On multiplayer servers, the server decides how players are verified and which skins are shown. For servers that don’t verify accounts, server-side mods such as SkinRestorer can be used to display skins.

Does Crit Launcher collect telemetry or personal data?

No. Crit Launcher currently collects no telemetry and no analytics. There are no tracking scripts, no ads and no bundled software.

If anonymous crash reports or version statistics are ever added in a future release, they will come with a clear opt-out toggle in the settings. Your files, account tokens and identity stay on your computer.

What does Crit Launcher connect to?

Only the services its features need:

• Mojang and Microsoft: sign-in, game files and official vanilla assets.
• Modrinth and CurseForge: searching and downloading mods, modpacks, resource packs and shaders.
• Skin and avatar services (such as Minotar and mc-heads): showing player heads and skins in the interface.

None of these connections send analytics to the Crit Launcher team.

Why do some antivirus programs flag Crit Launcher?

Crit Launcher is a new project and is not yet signed with a code-signing certificate, which costs money. Security software tends to distrust unsigned programs from new publishers. The launcher also does things that heuristic scanners watch for, such as downloading Java runtimes and starting other programs.

As a result, tools like Windows Defender or Malwarebytes may show warnings such as “PUP” (potentially unwanted program) or a generic trojan detection. These are false positives. We plan to buy a code-signing certificate, which should reduce them.

You don’t have to take our word for it. The source code is public, and the next question explains how to check that your download is genuine.

How can I verify my download is genuine?

Compute the SHA-256 hash of the file you downloaded and compare it to the checksum published with the release on GitHub. If they match, your file is identical to the official one.

Windows (PowerShell)

Get-FileHash .\CritLauncher.exe -Algorithm SHA256

Linux (terminal)

sha256sum crit-launcher-bin

If you would rather not trust a prebuilt file at all, you can build Crit Launcher yourself from the public source code.

How do I report a security problem?

Please report vulnerabilities privately instead of opening a public issue. The steps are in our security policy.