MelonLoader

MelonLoader is a free mod loader for Unity games that use Mono or Il2Cpp. It supports mods and plugins, with load-order control and dependency handling. The repository directs users to place mods and plugins in separate folders in the game installation directory, and logs go into a MelonLoader/Logs folder. Installation guidance covers an installer and manual setup from a release archive. For Il2Cpp games, the listed requirement is the .NET 6.0 Desktop Runtime; the repository says Windows installs it automatically. Windows loading uses a proxy DLL when the game starts, and that mechanism is Windows-only. Linux guidance covers WINE, Steam Proton, and native use, while Android and Oculus Quest support is marked as work in progress. Debug mode is intended for developing and debugging the loader, mods, and plugins. Configuration also includes a Mono debug server, and the Il2Cpp Assembly Generator can be set to work without contacting its remote API. MelonLoader is licensed under Apache License, Version 2.0.

MelonLoader offers a free route to managing mods and plugins for compatible Unity games, with separate installation guidance for different environments. Android and Oculus Quest support remains in progress.

It suits people who want to load mods or plugins in Unity games that use Mono or Il2Cpp. Developers may also find its debug mode and logging useful.

MelonLoader is a free injection-based loader for Unity games that use Mono or Il2Cpp. It is best suited to players adding supported mods and plugins, as well as developers who need debugging tools. Its broad Unity runtime coverage and load-order controls make it a practical choice, provided your game and platform are supported.

Overview

MelonLoader loads mods and plugins into compatible Unity games, keeping them in separate Mods and Plugins folders in the game’s installation directory. Load-order control and dependency handling help when several add-ons need to work together, but they do not make MelonLoader a general-purpose mod manager: it is for Unity games using Mono or Il2Cpp.

Installation can follow an installer guide or be done manually from a release archive. Logs are written to a MelonLoader/Logs folder inside the game directory, giving users a defined place to check when troubleshooting. The Il2Cpp Assembly Generator can be configured to run without contacting its remote API, a useful option for offline setups.

Key features

• Mono and Il2Cpp support: One loader covers both Unity runtime types, so runtime choice alone does not require a different tool.
• Organized add-on loading: Separate folders for mods and plugins, plus load-order control and dependency handling, suit multi-add-on setups.
• Debug mode: Intended for developing and debugging MelonLoader, plugins, and mods; its value is greater for creators and maintainers than for players who only install add-ons.
• Configuration and logs: Logs go to a dedicated folder in the game directory. The configuration includes a Mono debug server with a default listen address of 127.0.0.1 and port 55555.

Pricing

MelonLoader: free (Apache License 2.0). The free plan includes the loader without a trial period or a paid tier to weigh against it. Apache License 2.0 governs MelonLoader; the repository also identifies HarmonyX and MonoMod, two third-party libraries, as MIT licensed. No seat or quota terms apply in the published plan.

Platforms

MelonLoader supports Windows, Linux, and macOS. Linux guidance covers WINE, Steam Proton, and native use. On Windows, it uses a proxy DLL to load when the game starts; that mechanism applies only to Windows. For Il2Cpp games, the stated requirement is the .NET 6.0 Desktop Runtime, which the page says is installed automatically on Windows.

Android and Oculus Quest support are marked as work in progress, so players on those platforms should not treat them as established options. Supported games must be Unity titles built on Mono or Il2Cpp.

Who it's for

MelonLoader is a strong fit for players whose Unity games have compatible mods or plugins, particularly when their setup needs load-order control or dependency handling. Developers may also value the debug mode, logs, and configurable Mono debug server. It is not the right choice for games outside Unity, and Android or Oculus Quest users should wait for support to mature.

Pros and cons

Pros

• Free and openly licensed: The plan costs nothing, and the project uses Apache License 2.0.
• Works across both Unity runtime types: Mono and Il2Cpp support broadens its usefulness among compatible Unity games.
• Useful controls for larger setups: Load-order control and dependency handling help coordinate multiple mods and plugins.
• Installation and troubleshooting paths: Users can choose guided or manual installation and have a designated log folder for diagnosis.

Cons

• Limited to compatible Unity games: It does not serve as a general loader for other game engines.
• Android and Quest support is unfinished: Players on those platforms cannot count on mature support.
• Il2Cpp has a runtime prerequisite: The .NET 6.0 Desktop Runtime is required, even though Windows installs it automatically according to the page.

Alternatives

For a broader selection, browse Game Mod Loaders. Consider SMAPI instead for its own supported games; its free plan requires Stardew Valley 1.6.14 or later on Linux, macOS, Windows, or Steam Deck. CLEO is another free option for Windows and iOS.

Satisfactory Mod Loader is free and supports Linux and Windows, with no required dependencies; its stated scope includes Windows client and server and Linux server. BepInEx may suit users seeking a free, open-source loader with manual installation and stable or bleeding-edge builds across Linux, macOS, and Windows.

Cyber Engine Tweaks is a free, MIT-licensed framework for Linux and Windows. Hell2Modding is a free alternative for macOS and Windows. ModTek is a free mod loader for the BattleTech PC game on Linux, macOS, and Windows. MWSE is free software under the GNU GPL for Linux and Windows, and welcomes contributions including ideas, bug fixes, documentation, and new features.

Verdict

Choose MelonLoader if you want a free way to load mods and plugins into a compatible Unity game and value support for both Mono and Il2Cpp. Its loading controls, debugging features, and installation options make it a capable choice for players and developers alike. Look elsewhere if your game is not a supported Unity title, or if you need established Android or Oculus Quest support.