Onyx Launcher
Onyx Launcher is a free, open-source desktop launcher for Minecraft on Windows and Linux.
What Onyx Launcher is
Onyx Launcher is a free, open-source desktop launcher for Minecraft on Windows and Linux. It manages separate game instances and supports Vanilla, Fabric, NeoForge, Forge and Quilt. Users can browse, install and update Modrinth mods and modpacks in its built-in catalog, and the launcher supports modpack imports. It can detect, download and isolate Eclipse Temurin Java 8, 17 or 21 as needed, and automatic updates are supported. Diagnostic tools measure in-game FPS, average frame times and stutters, analyze logs, and track memory and garbage-collection pauses. Crash Bisect searches controlled launches for conflicting mods, while World Guard makes safety snapshots before risky operations and supports rollbacks. When Minecraft launches, Ghost Mode unloads the launcher window, WebContents and GPU processes from system memory. Microsoft sign-in uses OAuth Device Flow; Onyx says it does not handle the user's password. Offline mode with custom skins is also available. The project is MIT licensed and describes itself as independent and unaffiliated with Microsoft, Mojang Studios or Modrinth. Windows builds are currently unsigned, and SmartScreen may display a warning.
Good
- Supports five loaders, including Vanilla.
- Built-in catalog handles Modrinth mods and modpacks.
- Automatically manages Eclipse Temurin Java versions.
- World Guard supports safety snapshots and rollbacks.
Watch out
- Windows builds are currently unsigned.
- Available for Windows and Linux only.
Who it suits
It suits Minecraft players on Windows or Linux who want to manage instances, loaders and Modrinth content from one launcher. Its diagnostic and rollback tools may also appeal to players who troubleshoot mod conflicts or risky operations.
Verdict
Onyx Launcher brings instance management, modpack tools and diagnostics together at no cost. Windows users should account for the unsigned-build warning and check the published SHA-256 checksum.
Plans and prices
From Onyx Launcher's own pricing page, checked 8 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Free and open source | Free | 100% Free & Open Source · MIT licensed |
The facts
Each one read from Onyx Launcher's own pages, with the date it was checked.
What it does
- Account sign-in
- Microsoft sign-in uses OAuth Device Flow, and Onyx says it never handles the user's password; offline mode with custom skins is also available.checked 8 Oct 2026
- Automatic updates
- Yeschecked 19 Sep 2026
- Built-in modpack catalog
- Yeschecked 19 Sep 2026
- Crash diagnostics
- Onyx analyzes logs and tracks memory and garbage-collection pauses, and Crash Bisect searches controlled launches for conflicting mods.checked 8 Oct 2026
- Download integrity
- GitHub releases publish SHA-256 checksums alongside binaries, and the maker says builds are compiled through public GitHub Actions CI.checked 8 Oct 2026
- Ghost Mode
- When Minecraft launches, Ghost Mode unloads the launcher window, WebContents, and GPU processes from system memory.checked 8 Oct 2026
- Java runtime
- Onyx automatically detects, downloads, and isolates Eclipse Temurin Java 8, 17, or 21 as needed.checked 8 Oct 2026
- Java runtime management
- Yeschecked 19 Sep 2026
- License and affiliation
- Onyx is MIT licensed and says it is independent and unaffiliated with Microsoft, Mojang Studios, or Modrinth.checked 8 Oct 2026
- Loaders
- The launcher supports Fabric, NeoForge, Forge, Quilt, and Vanilla.checked 8 Oct 2026
- Mod catalog
- Users can browse, install, and update Modrinth mods and modpacks from the launcher.checked 8 Oct 2026
- Mod loader support
- multiplechecked 19 Sep 2026
- Modpack import
- bothchecked 19 Sep 2026
- Performance telemetry
- Onyx Probe measures in-game FPS, average frame times, and stutters through a bundled Java agent.checked 8 Oct 2026
- Separate instances
- Yeschecked 19 Sep 2026
- Support
- The launcher offers redacted support bundles for troubleshooting.checked 8 Oct 2026
- Unsigned builds
- Windows builds are currently unsigned, so SmartScreen may show a warning; the site advises checking the published SHA-256 checksum.checked 8 Oct 2026
- What it does
- Onyx is an open-source desktop Minecraft launcher built with React and Electron.checked 8 Oct 2026
- World safety
- World Guard makes safety snapshots before dangerous operations and supports safe rollbacks.checked 8 Oct 2026
Money
- Free plan
- Yeschecked 19 Sep 2026
Where it runs
- Supported platforms
- The download page lists Windows 10/11 x64 and modern Linux x64, with AppImage, .deb, .rpm, and portable archive options for Linux.checked 8 Oct 2026
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