server.properties

server.properties is a plain text file in the root folder of every Minecraft Java server. The server creates it on first start with default values. Each line is a key=value pair; lines starting with # are comments.

Settings worth knowing

• motd: the message shown under the server name in the multiplayer list.
• gamemode, difficulty, hardcore, pvp: the basic rules of the world.
• max-players: how many players can be online at once.
• server-port: the port the server listens on, 25565 by default. See port and SRV record.
• online-mode: whether players are authenticated with Mojang’s servers. Keep it true unless the server runs behind a proxy such as Velocity.
• white-list and enforce-whitelist: restrict access, see whitelist.
• view-distance and simulation-distance: the biggest performance levers in this file.
• level-name and level-seed: the world folder name and the seed used when a new world is generated.
• spawn-protection: the radius around spawn that only operators can build in.
• enable-rcon, rcon.port, rcon.password: remote console access, see RCON.
• op-permission-level: the default level given by /op, see op.

Why it matters for server owners

Most first questions about a server, such as how to change the difficulty, rename the server in the list or stop people from joining, are answered in this file. Performance issues often start here too.

Editing safely

• Stop the server first. The server reads the file at startup, and some versions rewrite it on shutdown, which can overwrite your edits.
• Keep the exact key names and the key=value format; typos are ignored silently.
• Change one thing at a time and restart, so you know which change caused what.

Practical tip

Keep a copy of a working server.properties with your backups. When something breaks after an edit, comparing the two files is the fastest way to find the cause.