Server-Side vs. Client-Side Mods
Understand which mods need to go on your server, which matter on the player's end and which need both.
Understand which mods need to go on your server, which matter on the player's end and which need both.
Introduction
"I installed the mod but nothing changed." and "Why can't my friend join anymore?" are the two most common questions when it comes to mods and they usually come down to the same misunderstanding: Not every mod belongs in the same place.
The Three Types of Mods
Server-Side Mods: Runs entirely on your server, no mods needed on your client. This can be performance mods, anti-cheat, world management and moderation tools.
Client-Side Mods: Only changes what's shown on the player's screen. Minimaps, shaders, zoom mods, UI tweaks and more. The server doesn't need to know about them, however installing them server-side has no effect either.
Both Required: Most content falls here. New blocks, items, mobs or mechanics need matching code on both ends so clients and servers agree on what exists. If it's missing on either side, players can't join or things break.
Telling the Difference
CurseForge and Modrinth label every mod page with Client, Server or Client and Server tags, check there first.
As a rule of thumb:
- Adds new blocks, items or mechanics → Needs both sides
- Only changes visuals, sound or HUD → Client-Side
- Only affects server logic, world generation or performance → Server-Side
When unsure, check the mod's description since most authors will state this outright.
What Goes Wrong When Mixed Up
- Client-Side Mod on the Server: Wastes upload space, does nothing.
- "Client and Server" Mod only on the server: Players can't connect or see broken/missing content.
- "Client and Server" Mod only on the client: You may get disconnected or see items the server doesn't recognize.
Quick Reference
| Mod Type | Install On | Example |
|---|---|---|
| Server-Side | Server only | Performance/Optimization Mods |
| Client-Side | Client only | Minimaps, Shaders |
| Both required | Server + Every Player | Content/Gameplay Mods |
On MCServerHost
When uploading mods through your dashboard using this installation guide, you only need the server-side and both-required mods. Client-side mods are up to each player and never need to touch your server files.
One thing that people still mess up: Versions must match exactly. A both-required mod in a different version or a different loader (Forge vs. Fabric) between server and client will still fail. Keep everyone on the same mod and loader version.
Related guides
- How to Install Plugins on Your Server: Installing plugins on your server is quick and straightforward. This guide covers the two main methods to get your plugins up and running.
- How to Set Up BlueMap on a Minecraft Server: Learn how to set up BlueMap on your Minecraft server.
- How to Set Up DriveBackupV2 on a Minecraft Server: Learn how to configure DriveBackupV2 to automatically back up your Minecraft server.
- How to Set Up MythicMobs on a Minecraft Server: Learn how to install and configure MythicMobs to create custom mobs and bosses on your Minecraft server.