MelonLoader

Overview

MelonLoader injects into compatible Unity games and supports both Mono and Il2Cpp, giving players a common loader across those two runtimes. It is a focused tool rather than a general mod manager: games outside Unity are beyond its stated scope.

Mods and plugins go in separate folders within the game installation directory, while load-order control and dependency handling help with setups that have multiple add-ons. Installation can follow an installer guide or be done manually from a release archive. Logs are written to a MelonLoader/Logs folder in the game directory, a useful place to start when troubleshooting.

Debug mode is intended for developing and debugging MelonLoader, plugins, and mods, making the loader relevant to creators as well as players. For Il2Cpp games, the requirement is the .NET 6.0 Desktop Runtime; the page says Windows installs it automatically. The Il2Cpp Assembly Generator can be configured to work without contacting its remote API, an option for users who need offline operation.

Key features

• Mono and Il2Cpp support: Covers both Unity runtime types, so runtime choice alone does not force users to seek a different loader.
• Separate mod and plugin loading: Dedicated Mods and Plugins folders keep add-ons distinct; load-order control and dependency handling are useful when several are installed together.
• Installation choice: An installer guide and manual release-archive instructions accommodate different installation preferences, though manual installation puts more of the process in the user's hands.
• Development and diagnostics: Debug mode and game-directory logs give mod and plugin developers relevant tools beyond basic loading. Configuration includes a Mono debug server listening by default at 127.0.0.1 on port 55555.
• Offline generator option: The Il2Cpp Assembly Generator can run without contacting the remote API, useful where that network access is unwanted or unavailable.

Pricing

MelonLoader costs 0.00 USD per free under the Apache License 2.0. There is no paid tier or trial to weigh against the free option; the stated scope is Unity games using Mono or Il2Cpp. Its open-source license and zero price suit players who want a no-cost loader, while the license does not remove the need to check whether a particular game and platform are supported.

Platforms

MelonLoader supports Windows, Linux, and macOS, with Android and Oculus Quest marked as work in progress. Linux guidance covers WINE, Steam Proton, and native use, giving Linux users more than one route to consider. Windows uses a proxy DLL to load at game startup; that mechanism applies only to Windows, so it should not be assumed to describe installation on other systems. For Il2Cpp games, the .NET 6.0 Desktop Runtime requirement matters, although Windows installs it automatically.

Who it's for

MelonLoader is a strong fit for players whose target game is a Unity title using Mono or Il2Cpp and who need mod or plugin support, particularly when managing several add-ons. It also suits developers who need a debug mode, a Mono debug server, and logs in a predictable game-directory location. It is a weaker choice for anyone seeking a loader for non-Unity games or relying on Android or Quest support today, since those platforms are still in progress.

Pros and cons

• Pro: Broad Unity runtime coverage. Mono and Il2Cpp support serves two runtime types within the same focused loader.
• Pro: Useful for multi-add-on setups. Separate folders, load-order control, and dependency handling address practical organization needs.
• Pro: Developer-oriented diagnostics. Debug mode and game-local logs help creators work on mods and plugins as well as load them.
• Con: Android and Quest are not mature targets. Both are marked as work in progress, so users who need established support there should look elsewhere.
• Con: The scope is limited to Unity. Players modding games built on other engines need a different tool.
• Con: Il2Cpp adds a runtime prerequisite. The .NET 6.0 Desktop Runtime is required, even though Windows handles installation automatically.

Alternatives

Browse Game Mod Loaders for more options. Choose SMAPI instead when Stardew Valley is the target: it is free and supports Android, Linux, macOS, and Windows, with a requirement of Stardew Valley 1.6.14 or later on Linux, macOS, Windows, or Steam Deck. BepInEx is another free option for Linux, macOS, and Windows, with manual installation and stable and bleeding-edge builds.

MWSE is a free, open-source loader that welcomes contributions including ideas, bug fixes, documentation, and new features. For a BattleTech PC game mod loader, consider ModTek, which is free and supports Linux, macOS, and Windows. Satisfactory Mod Loader is free, has no required dependencies, and supports Windows client and server use plus Linux servers. Hell2Modding is a free option for macOS and Windows. Everest is free and supports API, Linux, macOS, and Windows; Northstar is free for Linux and Windows.

Verdict

Choose MelonLoader when you want a free loader for a Unity game using Mono or Il2Cpp, especially if you need plugin support, add-on ordering, or developer debugging tools. Its runtime coverage and practical organization make it a capable focused choice; look elsewhere if your game is not built on Unity or you need Android or Oculus Quest support now.