How to install mods on a Minecraft server

Mods need a mod loader. A mod made for Fabric does not load on Forge, and a mod made for 1.21.1 does not load on 26.1, so the loader and the version come first. Pick the loader that the mods you want are made for; Fabric, Forge or NeoForge explains the difference.

1. Make a backup in the Backups tab.
2. Open Settings and go to Server software.
3. Choose Fabric, Forge or NeoForge as the server type and pick the Minecraft version your mods are made for.
4. Save and start the server once, so it creates the mods folder and its first files.

Paper, Purpur and Spigot run plugins, not mods. If you only want a few extras and players should join with a normal game, plugins may be the easier road: see install plugins.

1. Open the Mods tab of your server.
2. Under Verified Modrinth catalog, type the name of the mod in Search mods, for example lithium or farmer's delight.
3. The results are matched to your server type and Minecraft version, so a mod that does not fit your server does not show up.
4. Click Verify & install. The panel checks the file and puts it in /mods.
5. Restart the server to load it.

Every mod in the mods folder shows in the list above the catalog, with its file name and size. Filter installed mods finds one quickly when the list gets long.

For a mod that is not in the catalog, or a version you picked yourself:

1. On the mod's download page, pick the file for your loader and your exact Minecraft version. Mods are .jar files.
2. Stop the server.
3. In Files, open the mods folder and click Upload.
4. Choose the .jar file. Do not unpack it.
5. Start the server and watch the console while it loads.

Download mods only from the mod's own page on a known mod site. A .jar from a random link runs with full rights on your server.

Downloading a mod to your computer and uploading it again is not always needed. Two quicker ways:

• From link: copy the direct download link of the .jar on the mod page, open the mods folder in Files, click From link and paste it. The server fetches the file itself.
• SFTP: for twenty or fifty mods at once, create an SFTP password in the Files tab, then connect with a program such as FileZilla or WinSCP, using the details the panel shows. Then drag the whole set of .jar files into mods in one go.

Either way, stop the server first, and start it after the last file has arrived, so it does not load half a mod list.

Many mods need another mod to work, a library that holds shared code. The mod page lists these as dependencies. Without them the server stops at startup and the console names the mod that is missing.

• Fabric API is needed by almost every Fabric mod. Install it first on any Fabric server.
• Libraries such as Architectury, Cloth Config or GeckoLib come up often; install the version for the same loader and Minecraft version.
• A dependency marked optional adds extra features, but the mod starts without it.

When a modded server stops during startup, the reason is almost always in the last lines of the console, and the panel keeps the full log in the logs folder. These are the messages we see most and what they mean.

When the log is unclear, remove the mods you added last, start again, and add them back one at a time. The mod that brings the crash back is the one to look at. Minecraft server won't start covers startup problems that have nothing to do with mods.

Not every mod belongs in the same place. The mod page usually says where it runs.

A mod that only runs in the game, such as a shader loader, should stay off the server: at best it does nothing there, at worst the server refuses to start. Pre-generating the world with Chunky is covered in pre-generate your world.

A short list of mods that are worth having on almost any modded server. None of them changes the gameplay, so players do not need them in their own game.

Not every mod exists for every Minecraft version. Search for them in the Mods tab; when one does not show up for your version, the mod page lists which versions it supports.

When a content mod is missing or has another version in a player's game, the player cannot join and sees a list of what does not match. Two ways to keep everyone equal:

• Make a small modpack with the same mods and versions, and share it with your players. Their launcher installs it in one go.
• Keep a list of every mod with its exact version, and have players install the same files.

Join a modded server is the guide to send your players; it covers the launcher and the memory their game needs.

The easiest way to give friends exactly the mods of your server is a modpack file they can import in one click. The free launchers can make one:

1. In the Modrinth App, the CurseForge app or Prism Launcher, make a new profile that uses the loader and Minecraft version of your server.
2. Add the same content mods, in the same versions as on the server. Graphics mods such as Sodium can go in as well; the server does not mind them in the players' games.
3. Export the profile as a modpack: a .mrpack file in the Modrinth App, a .zip in the CurseForge app.
4. Send the file to your players. They import it in their launcher, start it, and join with the address of your server.

When you add or update a mod on the server later, export the pack again and send the new file, so nobody is left on an old version.

• Remove: click Remove next to the mod in the Mods tab and restart. The panel says "Mod removed. Restart to apply."
• Update: remove the old file and install the new one. Two versions of the same mod in mods stop the server from starting.
• Make a backup first. Removing a content mod also removes its blocks and items from the world, and that cannot be undone without the backup.
• Update the same mods in your players' games at the same time, or they cannot join.

A new Minecraft version means a new file of every mod, and some mods take weeks or months to catch up. Check before you switch:

1. Make a backup in the Backups tab first, because a world never returns to an older version once a newer one has opened it.
2. Check every mod on its page for a file for the new version. If an important content mod is missing, wait: without it, its blocks and items disappear from the world.
3. Change the Minecraft version in Settings under Server software, then replace every mod in mods with the file for the new version.
4. Start the server and read the console until it says Done. Then update the modpack or mod list of your players.

Change your Minecraft server version explains the version switch itself in more detail.

Every mod takes some memory. A handful of light mods runs well on the RAM of a normal server; a large collection of content mods needs about as much as a heavy modpack, 12 to 16 GB. How much RAM for a Minecraft server has the full table, and reduce lag helps when a modded server feels slow.

Bedrock has no mods in the Java sense. The official Bedrock server takes add-ons instead: behavior packs and resource packs that are uploaded to the server and switched on for a world. They are made for Bedrock only, and Java mods do not work there. On this hosting a Bedrock server runs Paper with Geyser, like a crossplay server, so it takes plugins and not add-ons.

A crossplay server runs Paper with Geyser, so it takes plugins rather than mods. If you want Bedrock friends to join, pick plugins for the extras; if you want mods, the server runs Fabric, Forge or NeoForge and everyone plays Java. Java or Bedrock server helps you choose.