Supported Minecraft versions and mod loaders
Poly Mod Loader 1.4.0 runs Minecraft: Java Edition 26.1, 26.1.1, 26.1.2, 26.2, 26.3 on Java 25. It runs Poly Mods, Fabric mods, Forge mods, NeoForge mods and Quilt mods. Fabric and Quilt mods also run in one game with Forge mods or with NeoForge mods, except those whose mixins do not fit that loader's patches (on 26.2: three Fabric mods next to Forge, 10 Fabric API modules next to NeoForge). Forge and NeoForge mods do not run in the same game yet. On Minecraft 26.3, mixing loaders works since 1.2.5.
Minecraft versions
| Minecraft | How Poly Mod Loader runs it | Forge version it runs for Forge mods | NeoForge version it runs for NeoForge mods |
|---|---|---|---|
| 26.3 | Its own version modules (since 1.2.0). Popular-mod sets run headless, one loader at a time (2026-10-27) and mixed (since 1.2.5, 2026-10-28; below) | 66.1.0 | 26.3.0.98 |
| 26.2 | Its own version modules. The default version in these docs | 65.1.5 | 26.2.0.93 |
| 26.1 | Its own version modules | 62.0.9 | 26.1.0.19-beta |
| 26.1.1 | A hotfix that runs on the 26.1 modules | 63.0.2 (no separate test mod set) | 26.1.1.15-beta (no separate test mod set) |
| 26.1.2 | A hotfix that runs on the 26.1 modules | 64.1.5 | 26.1.2.122 |
NeoForge has only beta builds for 26.1 and 26.1.1; Poly Mod Loader uses the last one. Forge's and NeoForge's files are downloaded on the first start with their mods.
Every version runs on Java 25. The installer offers all five versions, for the launcher profile and for a dedicated server.
Versions that are not in this table are not supported, including all 1.x versions. Since Minecraft 26.1, Mojang ships Java Edition unobfuscated, so mods from every loader use the same names (Mojang's original names) on these versions.
Loaders
| Mods | Status | What it means today |
|---|---|---|
| Poly Mods (Native API) | Verified | Client, server, and world saving are checked |
| Fabric mods | Verified | Entry points, the Fabric Loader API, language adapters, nested jars, Mixin and MixinExtras, class tweakers, and @Environment work as in Fabric Loader. Mods may depend on Poly Mods and other Fabric mods |
| Fabric mods that use Fabric Loader's internal classes | Partial | The parts real mods use are provided (FabricLauncherBase.getLauncher(), FabricLoaderImpl.getGameProvider()). A mod that needs the rest is left out with a reason (POLY-COMPAT-111) |
| Forge mods | Verified | On 26.1–26.3. Poly Mod Loader runs Forge and FML themselves. Mods that Forge would refuse are left out first, with the reason (POLY-COMPAT-209) |
| NeoForge mods | Verified | On 26.1–26.3 (popular-mod set tested on 26.1, 26.1.2 and 26.2, and headless on 26.3). Poly Mod Loader runs NeoForge and its loader FML themselves. Mods that NeoForge would refuse are left out first, with the reason (POLY-COMPAT-217), instead of stopping the launch. NeoForge mods run next to Poly Mods, Fabric mods and Quilt mods, with the limit in the last row of this table (POLY-COMPAT-224). Not yet in the same game as Forge mods: then Forge runs and the NeoForge mods are left out with the reason (POLY-COMPAT-221). Details: NeoForge |
| Quilt mods | Verified | On 26.1–26.3 (popular-mod set tested on 26.1, 26.1.2 and 26.2, and headless on 26.3). quilt.mod.json is read with Quilt Loader's meaning, the Quilt Loader API (org.quiltmc.loader.api) is provided, and Quilt mods' nested jars, entry points, Mixin and access wideners work. They run next to Fabric mods and Poly Mods, and next to Forge and NeoForge mods with the limit in the next row. Quilt Standard Libraries (QSL) has no release for 26.x, so mods that need it are left out (POLY-COMPAT-114 with 308). A jar with both quilt.mod.json and fabric.mod.json runs as a Fabric mod (310). Details: Quilt |
| Fabric and Quilt mods next to Forge or NeoForge mods | Partial | Since 2026-10-25, a Fabric or Quilt mod whose mixins cannot work as written on the game Forge or NeoForge patched is not loaded (POLY-COMPAT-224), and neither are the mods that need it (POLY-COMPAT-114). The title screen says how many. On 26.2, no Fabric API module is left out next to Forge, but Architectury, Balm and Lithium are (1.2.5, 2026-10-28); next to NeoForge, 10 Fabric API modules are left out. On 26.3 this works since 1.2.5 (headless, 2026-10-28). Details: Run Fabric and Forge mods together |
Status definitions: Verified / Partial / Experimental / Blocked / Untested. A jar that merely loaded is never labeled Verified. Every jar is either loaded or left out with a reason before game code runs; the reason goes to the log and to .poly/startup-report.json.
Results per version
The test set is the most downloaded mods on Modrinth for each Minecraft version, plus the mods they require. The checks are: load, start, join or create a world, tick, save, and quit. Each mod's features were not checked one by one.
Fabric mods
| Check | 26.2 | 26.1 |
|---|---|---|
| Client: join a saved world, 200 ticks, save and quit to title, stop | 140 mods | 128 mods |
| Real dedicated server start, up to the EULA check | 100 | 93 |
| Game test server: create a world, GameTest, tick, save | 98 | 91 |
The client counts include 2 test mods that drive the run. The only directly installed Fabric mods left out are ones Fabric Loader refuses too.
Forge mods
| Check | 26.2 (Forge 65.1.5) | 26.1 (Forge 62.0.9) | 26.1.2 (Forge 64.1.5) |
|---|---|---|---|
| Client: join a saved world, 200 ticks, save and quit | 40 | 26 | 36 |
| Game test server: create a world, GameTest, save | 32 of 38 | 18 of 36 | 28 of 34 |
| Dedicated server, up to the EULA check | 35 of 41 | 19 of 37 | 31 of 37 |
| Next to Fabric mods, game test server | 2026-10-28 (1.2.5): 88 mods of the other loaders loaded, 78 left out (1.2.4: 87 and 79; 2026-10-25: 42 and 124; before: 33 of 39 Forge mods next to 90 Fabric mods) | 2026-10-28 (1.3.0): 76 mods of the other loaders loaded, 80 left out | 2026-10-28 (1.3.0): 83 loaded, 81 left out |
The Forge mods left out are ones real Forge also leaves out or cannot run: client-only mods on a server, mods built for another Forge, Minecraft, or language loader version (9 on 26.1, all built for 26.1.2), and Mixin configurations that stop Forge's own Mixin. FML stops loading every mod when even one such mod is present; Poly Mod Loader leaves out only that mod.
NeoForge mods
| Check | 26.2 (NeoForge 26.2.0.93) | 26.1 (NeoForge 26.1.0.19-beta) | 26.1.2 (NeoForge 26.1.2.122) |
|---|---|---|---|
| Client: join a saved world, 200 ticks, save and quit | 54 | 36 | 55 |
| Game test server: create a world, GameTest, save | 38 | 31 of 35 | 40 |
| Dedicated server, up to the EULA check | 37 | 30 of 34 | 39 |
| Installed launcher profile (client) | 2 test mods | not run | 54 |
| Next to Fabric mods, client: join a saved world, 200 ticks, save and quit | not run again since 2026-10-25 | not run again since 2026-10-25 | not run again since 2026-10-25 |
| Next to Fabric mods, game test server | 2026-10-27 (1.2.4): 40, with 40 mods of the other loaders loaded and 76 left out (2026-10-25: 48, with 28 Fabric mods; before: 54) | not run again since 2026-10-25 | not run again since 2026-10-25 |
| Next to Fabric mods, dedicated server up to the EULA check | not run again since 2026-10-25 | not run again since 2026-10-25 | not run again since 2026-10-25 |
| Next to Quilt mods (and their Fabric mods), game test server | 2026-10-25: 56, with 12 Quilt and 15 Fabric mods (before: 73 and 50) | not run again since 2026-10-25 | not run again since 2026-10-25 |
| Next to Fabric mods, a client joins over the network: login, configuration and play phase, both loaders' payloads | 2026-10-25: passes. Fabric API's registry sync is not loaded, so the server registers no fabric: channels | not run again since 2026-10-25 | not run again since 2026-10-25 |
Since 2026-10-25, Fabric and Quilt mods whose mixins do not fit NeoForge's patch are not loaded (POLY-COMPAT-224): on 26.2 with 1.2.4 (2026-10-27), 10 Fabric API modules (block, content-registries, crash-report-info, data-generation, entity-events, events-interaction, item, registry-sync, resource-conditions, transfer) and the mods that need them; on 2026-10-25 it was 16. The rows next to Fabric and Quilt mods were run again on 26.2 only, on the game test server (next to Fabric mods again on 2026-10-27) and for the network join; the other cells were not run again under this behaviour. The counts next to Fabric and Quilt mods include nested jars. Quilt mods next to NeoForge mods were checked on the game test server only. The server counts include a test harness mod that runs the game tests (NeoForge does not run Mojang's game tests in production). An installed server runs NeoForge mods on all four versions. The NeoForge mods left out are ones that also stop or are refused under NeoForge's own server, each checked against NeoForge's own install: client mods that stop a server (Sodium and the mods that use its classes, ImmediatelyFast's 26.2 build, Zoomify; they run on the client), and on 26.1 builds made for a later NeoForge (POLY-COMPAT-217) or that stop on NeoForge 26.1.0.19-beta. NeoForge stops loading every mod when one mod's version range does not match; Poly Mod Loader leaves out only that mod.
Quilt mods
The Quilt test set is every project on Modrinth with a Quilt build and no Fabric build for that Minecraft version, plus the mods those builds require: 114 and 3 required mods on 26.2, 97 and 1 on 26.1, 50 and 1 on 26.1.2. Most of them (65 on 26.2) are data packs packaged as mods. The counts below include nested and required mods.
| Check | 26.2 | 26.1 | 26.1.2 |
|---|---|---|---|
| Client: join a saved world, 200 ticks, save and quit | 155 mods (88 Quilt) | 131 (73 Quilt) | 88 (30 Quilt) |
| Game test server: create a world, GameTest, save | 135 (80 Quilt) | 118 (69 Quilt) | 73 (25 Quilt) |
| Dedicated server, up to the EULA check | 133 | 116 | 71 |
| Quilt-only builds loaded on the server | 93 of 114 | 79 of 97 | 34 of 50 |
| Next to Forge mods, in one game | 2026-10-25: 22 Fabric, 13 Quilt and 42 Forge mods (before: 51, 73 and 42) | not run again since 2026-10-25 | not run again since 2026-10-25 |
| Same result as real Quilt Loader 0.31.0-beta.4 (dedicated server) | 113 of 114 | 96 of 97 | 48 of 50 |
The Quilt mods left out are ones real Quilt Loader also leaves out or cannot run: metadata Quilt Loader refuses too, version ranges it does not accept either, client-only mods on a server, a jar that is not a mod, and on 26.1 and 26.1.2 a build compiled against Minecraft 1.21 names that fails as soon as it runs. An installed server runs a Quilt mod on all three versions, and an installed launcher profile on 26.2. Real Quilt Loader was not run on the client for comparison.
Minecraft 26.3 (headless: one loader at a time on 2026-10-27, mixed loaders on 2026-10-28 with 1.2.5; windowed client runs not done yet)
| Check (26.3) | Result |
|---|---|
| Fabric mods, game test server: create a world, GameTest, save | 98 loaded, 73 left out |
| Fabric mods, dedicated server up to the EULA check | 100 loaded, 74 left out |
| Forge mods (Forge 66.1.0), game test server / dedicated server | 30 of 38 / 33 of 41 |
| NeoForge mods (NeoForge 26.3.0.98, FML 12), game test server / dedicated server | 50 / 49 loaded |
| Quilt mods, dedicated server | 112 loaded, 34 left out; 73 of the 91 Quilt-only builds load |
| Same result as real Quilt Loader | 89 of 91 |
| Fabric mods next to Forge mods, game test server | 80 loaded, 86 left out (with 224: Architectury, Balm, Lithium, Puzzles Lib, three Fabric API modules) |
| Quilt mods next to Forge mods, game test server | 95 loaded, 86 left out |
| Fabric mods next to NeoForge mods, game test server / dedicated server | 40 / 39 loaded, 76 left out (10 Fabric API modules with 224) |
| Quilt mods next to NeoForge mods, game test server | 83 loaded, 96 left out |
The Forge mods left out on 26.3 are 7 client-only mods and InventoryProfilesNext, which needs libIPN that has no 26.3 build (real Forge refuses it too). The Quilt game test server run passes once five PurpurPacks data-pack mods that carry 26.2-format data are removed; that failure is on the mods' side. In 1.2.4, Fabric or Quilt mods next to Forge or NeoForge mods stopped at start on 26.3.
Running Fabric mods with Forge or NeoForge mods, with what still does not work: Run Fabric and Forge mods together. Every diagnostic and error code: Compatibility.