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How to Host a Modded Minecraft Server

Forge, Fabric, and modpacks like RLCraft and All the Mods — how to set them up, and how much RAM they really need.

Modded Minecraft is where the game gets truly custom — new dimensions, machines, magic, and hundred-mod packs like RLCraft, All the Mods, and Create-based worlds. Hosting a modded server is more involved than vanilla: you have to match the mod loader, the version, and enough RAM to keep it stable. This guide covers Forge and Fabric, installing individual mods and full modpacks, and what resources you actually need.

Forge vs Fabric: pick your mod loader

Mods do not run on a vanilla server — you need a mod loader, and the two dominant ones are Forge and Fabric. Forge is the long-established loader behind most large content modpacks (RLCraft, most All the Mods versions). Fabric is lighter and faster to update, popular for performance and smaller mods. Crucially, Forge mods and Fabric mods are not interchangeable: every mod you install must match both the loader and the exact Minecraft version. NeoForge, a Forge fork, is also increasingly common for newer packs.

Installing individual mods

To run a hand-picked set of mods on a Forge or Fabric server:

  1. Install the server build of your chosen loader (Forge, NeoForge, or Fabric) for the exact Minecraft version you want.
  2. Download each mod's server-compatible .jar from CurseForge or Modrinth, matching the same loader and version.
  3. Place every mod in the server's mods folder — including required library/dependency mods.
  4. Restart the server and watch the console for missing-dependency or version-mismatch errors, then fix and restart.

Installing a full modpack (RLCraft, All the Mods, etc.)

Most people run a curated modpack rather than assembling mods by hand. A modpack bundles dozens or hundreds of compatible mods plus configs. To host one, use the pack's server files: download the server pack from CurseForge or Modrinth, upload it to your server, and start it. On FluxCraft you get full file access, so you upload the server pack and launch it directly. Always use the version of the pack that matches what your players have installed in their launcher — mismatched pack versions will refuse to connect.

RAM: modded servers are hungry

This is the number one reason modded servers lag or crash. Mods load enormous amounts of content into memory, so a pack that runs fine on 4 GB for one player may thrash with a handful of players. As rough guidance: light packs want 4–6 GB, medium packs 6–8 GB, and heavy packs like RLCraft or large All the Mods versions need 8–12 GB or more. World generation and exploration in modded worlds is especially demanding — give the server generous RAM and expect to size up as the pack grows.

Keeping a modded server stable

Match every version exactly (loader, Minecraft version, and pack version), take backups before adding or updating mods, and update the whole pack at once rather than swapping single mods. Watch the server console after every change — modded crashes almost always name the culprit mod in the log. Because modpacks change so much between versions, a clean backup is your safety net.

Frequently Asked Questions

How much RAM does a modded Minecraft server need?

Light packs run on 4–6 GB, medium packs want 6–8 GB, and heavy packs such as RLCraft or large All the Mods versions need 8–12 GB or more.

What is the difference between Forge and Fabric?

Both are mod loaders, but their mods are not interchangeable. Forge powers most large content packs; Fabric is lighter and updates faster. Each mod must match the loader and Minecraft version exactly.

Can I run a CurseForge modpack on my server?

Yes. Download the pack's server files, upload them to your server, and launch. Make sure the pack version matches what players have in their launcher.

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