Onyx Launcher vs Refract

Onyx Launcher is a free, open-source desktop Minecraft launcher for Windows and Linux. It manages separate instances, imports modpacks and supports Fabric, NeoForge, Forge, Quilt and Vanilla. A built-in Modrinth catalog lets users browse, install and update mods and modpacks, while automatic updates and Java runtime management are included. Onyx can detect, download and isolate Eclipse Temurin Java 8, 17 or 21 as needed. Diagnostic features measure in-game FPS, average frame times and stutters, analyze logs, track memory and garbage-collection pauses, and use Crash Bisect to look for conflicting mods through controlled launches. World Guard creates safety snapshots before risky operations and supports rollbacks. Ghost Mode unloads the launcher window, WebContents and GPU processes from memory when Minecraft starts. Microsoft sign-in uses OAuth Device Flow, and offline mode with custom skins is available. Windows builds are currently unsigned; published SHA-256 checksums can be checked. The MIT-licensed project says it is independent of Microsoft, Mojang Studios and Modrinth.

Refract is a free launcher for organizing Minecraft modpacks on Windows, macOS, and Linux. It supports modpacks from Modrinth, CurseForge, and FTB, with a built-in catalog for finding compatible content. Multiple mod loaders are supported, and modpack import is available through both listed methods. Each pack runs in a separate instance, with its mods, resource packs, worlds, settings, and launch options kept apart. The launcher can install dependencies, update individual mods in place, manage Java runtimes, and apply automatic updates; worlds are preserved during updates. Existing libraries can be imported without mixing files or damaging saves. Users can choose themes, accent colors, sidebar layouts, Java versions, memory limits, and launch behavior. Refract is licensed under GNU GPL v3.0, and its application and website are developed in public. The project uses Tauri and Rust for its native shell. Discord supports player help and project discussions, while GitHub is used for bug reports, change proposals, and code contributions.