Step-by-step guides

Minecraft

Install a mod or a plugin

The Mods or Plugins tab searches Modrinth and installs the build made for your server.

1. Open the Versions tab and check your loader. Paper and Spigot load plugins; Fabric, Quilt, Forge and NeoForge load mods; Vanilla loads neither.
2. Open the next tab, named Plugins or Mods after that loader. Search by name, click Install, then restart the server to load the file.
3. For a file Modrinth doesn't carry, click Stop, wait for the Off state and upload the .jar to plugins or mods, through the Files tab or over SFTP.
4. Most Fabric mods need Fabric API, so install it with them. A mod built for another Minecraft version sits under Other versions in the same tab.
5. Start the server and read the Console from the top. The loader lists each mod it accepted and prints the exception for each one it refused.

What usually goes wrong A file in the wrong folder raises no error: the server starts and the feature is missing. Check the folder before you blame the jar. An incompatible version throws an exception near the top of the log, so copy that if you write to us.

Let your players connect

Since Minecraft 26.3 the whitelist is on by default, so add your players before you share the address.

1. In Overview, under Connect, copy the address. If your server has a name, the game finds the port by itself; otherwise the address ends with a colon and the port.
2. In the game: Multiplayer, Add Server, paste the address. Wait for the line starting with Done in the Console, because Minecraft accepts nobody before it.
3. In the Console, type whitelist add followed by the username, with no slash. The player doesn't need to be online. For an open server, type whitelist off.
4. Outdated client or Outdated server means the two versions differ. Read yours in the Versions tab, and the player picks the same one in their launcher.

What usually goes wrong You are not whitelisted on this server means the username isn't on the list (on Vanilla: You are not white-listed on this server): run whitelist add again with the exact spelling. Connection timed out means a stopped server or a wrong address: check the state in the Console, then copy the address again.

The first start

Your server starts on Paper. The Versions tab changes the loader and the Minecraft version.

1. We install the latest Paper. For Vanilla, Spigot, Fabric, Quilt, Forge, NeoForge or an older version, open the Versions tab before you invite your players.
2. The first start generates the world. The Console prints a line starting with Done when it finishes, and the server takes connections from then on.
3. For a specific seed, set level-seed and change level-name in server.properties (Files tab): the server generates a new world on the next start.
4. If the server stops while starting, scroll the Console up to the first error. OutOfMemoryError calls for fewer mods or more memory; an exception names the mod at fault.

What usually goes wrong A world opened by a recent version won't run on an older one: a 26.x world refuses to go back to 1.21.x. Keep the Back up before installing box ticked. A free server has no backups, so download the world before you switch.

Settings, operators and the whitelist

The server.properties file sets up the game, and the Console hands out the rights.

1. Open server.properties in the Files tab: difficulty, gamemode, max-players, motd, view-distance and white-list each take one line. Restart to apply them.
2. Leave server-ip, server-port and query.port alone: the panel rewrites those three lines on every start and your value would vanish.
3. Grant rights from the Console: op followed by the username, deop to take them away. An operator gets in while the whitelist is on and doesn't need to be listed.
4. Set enforce-whitelist to true to kick a connected player as soon as you take them off the list. The default, false, lets them finish their session.

What usually goes wrong Changing level-name deletes nothing: the server creates a new world and the old one stays on disk. If your players land in an empty world after a settings change, put the old value back and restart to find it again.

Backups and new worlds

Your world lives in the folder named by level-name, with two neighbours for the Nether and the End on some versions.

1. The world is named after level-name, world by default. Depending on loader and version, the Nether and the End sit inside it or next to it in world_nether and world_the_end: take all three if they exist.
2. For a copy, click Stop, wait for the Off state, select those folders in Files, compress them and download the archive.
3. On a paid server, the Backups tab keeps each night for 7 days. Back up now gives you two more copies of your own before a big change.
4. For a new world, change level-name in server.properties and restart. Put the old name back to reopen the old world.
5. To put a copy back, stop the server, return the folders under the same name, then start and join yourself before you tell your players.

What usually goes wrong A world copied while the server runs can open with regions missing, because the server keeps writing during the copy. If you can't stop it, type save-off then save-all flush in the Console, copy, and finish with save-on.