How to set up a modpack server

A modpack is a curated bundle of mods — sometimes 200+ of them — built on a specific Minecraft version and mod loader (usually NeoForge/Forge, sometimes Fabric). Running one for friends is one of the best experiences in Minecraft, and also one of the heaviest things you can ask a server to do.

Client pack vs server pack

This is the concept that trips most people up. The pack you play in your launcher is the client pack. Most major packs also publish a separate server pack — same mods, minus the client-only ones (shaders, minimaps), plus the loader installer.

You want the server pack, in the exact same version as the client pack your players use. A version mismatch between client and server is the most common cause of 'I can't connect' on modded servers.

The general setup

• ✦Download the server pack for your modpack from CurseForge, Modrinth or FTB
• ✦Upload its contents to your server's root folder
• ✦Accept the EULA: open eula.txt and set eula=true
• ✦Start the server — first boot takes a while as 200 mods initialize; that's normal
• ✦Have every player install the matching client pack, same version

Resources: don't undersize it

Big kitchen-sink packs realistically need 8–12 GB of RAM and benefit heavily from fast storage and strong single-core CPU performance. On 4 GB, a large pack will either crash on startup or spend its life garbage-collecting.

On QuishHost, modpacks are supported on the Pro plan (16 GB) and up — not because we want to upsell you, but because we'd rather say that upfront than rent you a plan your pack will choke on.

Keeping it running smoothly

• ✦Pre-generate the world — modded chunk generation is dramatically heavier than vanilla
• ✦Limit chunk-loaders and quarry-style machines; they keep chunks ticking while nobody is online
• ✦Update the pack only when the server pack for that version is out, and back up first
• ✦When the server crashes, read crash-reports/ — modded crashes almost always name the offending mod