Mods add new blocks, items, mobs and dimensions that fundamentally change Minecraft. Unlike plugins, mods require a modloader: Forge, NeoForge or Fabric. The choice depends on which mods you want and which Minecraft version you play.
Forge, NeoForge or Fabric?
| Forge | NeoForge | Fabric | |
|---|---|---|---|
| Versions | 1.7 to 1.21.11 | 1.21+ (including 26.x) | 1.14+ (including 26.x) |
| Mod library | Largest (decades of mods) | All NeoForge mods + many Forge via compat | Growing, strong in performance mods |
| Big modpacks | ATM9, RLCraft, older packs | ATM10, ATM11, Prominence II | Cobblemon, lighter packs |
| Performance | Heavier, longer startup | Slightly lighter than Forge | Lightest of the three |
Installation
- Select the modloader and Minecraft version in the Startup tab of the game panel.
- Set the Java version: Java 25 for 26.x, Java 21 for 1.20.5 to 1.21.11, Java 17 for 1.18 to 1.20.4.
- Start the server once to create the folder structure.
- Download mods from Modrinth or CurseForge.
- Upload the .jar files to
mods/. - Restart the server.
Memory requirements
- Light modpack (20 to 50 mods): 4 to 6 GB
- Medium (100 to 200 mods): 6 to 8 GB
- Heavy modpack (300+ mods, ATM10): 10 to 12 GB
- ATM11, heavy tech/magic packs: 12 to 16 GB
Server-side vs client-side mods
Not every mod belongs on the server. Performance mods like Sodium and Iris are client-side only. Putting them in the server mods/ folder causes crashes. The mod page on Modrinth or CurseForge always states whether the mod is server-side, client-side or both.
Do players need the same mods?
Yes. The client must run the exact same mods and versions. Point your players to the modpack on CurseForge, or create a server pack they import through a launcher like Prism or ATLauncher.
Can I mix plugins and mods?
With pure Forge, NeoForge or Fabric: no. Hybrid solutions (Mohist, Cardboard) exist but are unstable and unsupported by most mod developers. Choose plugins or mods; the two ecosystems are separate.
Why won't my modded server start?
The three most common causes: a mod is incompatible with your Minecraft version, a mod is missing a dependency, or the Java version is wrong. The console error always names the problem mod.
Modded servers start at the Gold plan (4 GB). For heavy packs we recommend Obsidian (8 GB) or higher.
