Questions from players
Questions about making mods are in the FAQ for mod developers.
Is this the PolyMC launcher?
No, absolutely not. Poly Mod Loader (or simply Poly) is a next-generation in-game Mod Loader, not an external game launcher. It has zero association or relation with the third-party "PolyMC launcher" (which suffered a security incident in 2022 and prompted users to migrate to Prism Launcher).
- Role: Poly is a mod loader (like Fabric, NeoForge, or Forge) that runs inside the Minecraft client and server to load and unite mods across ecosystems.
- Launcher compatibility: You can use Poly with your preferred launcher — the official Minecraft Launcher, Prism Launcher, Modrinth App, or CurseForge.
- Security & Transparency: Poly is 100% open-source under MPL-2.0. All code, commit history, build pipelines, and release checksums (SHA-256) are publicly inspectable on GitHub.
Is Poly Mod Loader free and open source?
Yes. It is free, and its source is open under the Mozilla Public License 2.0 on GitHub. Releases up to 1.1.0 were distributed under the earlier PolyLoader Non-Commercial License.
Which mods can I use?
| Mods | Status |
|---|---|
| Fabric mods | Supported on Minecraft 26.1, 26.1.1, 26.1.2, 26.2, 26.3 |
| NeoForge mods | Supported on Minecraft 26.1, 26.1.1, 26.1.2, 26.2, 26.3, also next to Poly Mods |
| Forge mods | Supported on Minecraft 26.1, 26.1.1, 26.1.2, 26.2, 26.3, also next to Poly Mods |
| Quilt mods | Supported on Minecraft 26.1, 26.1.1, 26.1.2, 26.2, 26.3, also next to Fabric mods. Mods that need the Quilt Standard Libraries (QSL) are left out because QSL has no release for 26.x |
| Mixing loaders (Fabric / Quilt + Forge or NeoForge) | Partial. Fabric and Quilt mods can be placed in mods/ alongside Forge mods or alongside NeoForge mods. Any Fabric or Quilt mod whose mixins do not fit that loader's patches yet (POLY-COMPAT-224) is left out before the game starts and counted on the title screen. Forge and NeoForge mods do not run in the same game yet (POLY-COMPAT-221). On Minecraft 26.3 since 1.2.5 (in 1.2.4 mixing loaders there stopped the game at start) |
| Poly Mods (made for Poly Mod Loader) | Supported on Minecraft 26.1, 26.1.1, 26.1.2, 26.2, 26.3 |
What was tested with which mods is in Compatibility.
Can I mix Fabric, Forge, NeoForge and Quilt mods in one mods folder?
- Fabric + Quilt: Yes, they run together.
- Fabric / Quilt + Forge, or Fabric / Quilt + NeoForge: Partly. Before the game starts, Poly Mod Loader checks every Fabric and Quilt mod's mixins against the classes Forge or NeoForge patched. If a mod's mixin does not fit that loader's patched code yet, Poly Mod Loader leaves that mod out (
POLY-COMPAT-224, plusPOLY-COMPAT-114for mods that depend on it) and shows Not loaded, Poly Mod Loader can't run them yet: N on the title screen. Measured on 26.2: next to Forge (1.2.5, 2026-10-28), no Fabric API module is left out, but Architectury, Balm and Lithium are, with the mods that need them. Next to NeoForge (1.2.4, 2026-10-27), 10 Fabric API modules are left out, so Fabric mods that need those modules are left out too. On Minecraft 26.3, mixing loaders works since 1.2.5 (popular-mod sets, headless, 2026-10-28); in 1.2.4 those games stopped at start. See Run Fabric and Forge mods together. - Forge + NeoForge: Not in the same game yet. If both are in
mods/, Forge runs and the NeoForge mods are left out (POLY-COMPAT-221).
Which Minecraft versions does it run?
Poly Mod Loader 1.4.0 runs Minecraft 26.1, 26.1.1, 26.1.2, 26.2, 26.3. Older versions such as 1.20.1 or 1.21.1 are not supported. See Supported versions and loaders.
Do I also need Fabric Loader, Quilt Loader, Forge or NeoForge?
No. Install only Poly Mod Loader. It provides the Fabric Loader and Quilt Loader APIs itself and runs Forge and NeoForge itself. The first start with a Forge or NeoForge mod downloads that loader's files, so it needs an internet connection.
What happens to a mod that cannot run?
It is left out before the game starts, and your other mods still start. The reason, with a POLY-… code, is in logs/latest.log and in .poly/startup-report.json in the launcher folder. Error codes explains each code.
Will every mod work?
That is not guaranteed. The tests check that popular mods load together, open or create a world, and save. The features of each mod were not checked one by one.
Does it back up my worlds?
Partly. Before loading a world, Poly Mod Loader makes the game's own backup (a zip in backups/) if Poly Mods were removed or changed version since the world was last played. Fabric and Forge mods are not part of this check, so back up worlds you care about yourself before you remove or update those mods.
Can I run it on a server?
Yes. The same installer sets up a dedicated server, which needs Java 25 or newer. You accept the Minecraft EULA yourself. A mod that both the server and the players use needs the same version on both sides. See Dedicated server.
Is there a Windows .exe installer?
No. Since 1.2.4 the installer is one .jar file, PolyModLoader-<version>.jar, for Windows, macOS and Linux, and it needs Java 17 or newer. The Windows .exe is gone; releases up to 1.2.3 keep theirs. Get the installer only from the download page or the GitHub release, which also has SHA256SUMS.txt to check the file against.
How do I remove it?
Click Uninstall in the installer, or run java -jar PolyModLoader-<version>.jar uninstall. This removes the Poly Mod Loader version, its launcher profile and its files. Your mods/ folder and your worlds stay.
What should I do if something goes wrong?
See If something goes wrong in the install guide. If that does not help, report the bug on GitHub Issues with the error code and a link to logs/latest.log.