server.properties explained: the settings that matter

Where the file is and how to edit it

server.properties sits in the main folder of every Java server. Open it in a text editor, your server panel’s file manager, or download it via SFTP.

Three rules:

• Stop the server first, or restart it after saving. The server only reads the file at startup, and may overwrite changes made while it runs.
• One setting per line, written as key=value. No spaces around the =.
• Lines starting with # are comments.

Bedrock Dedicated Server has its own server.properties with different keys. This guide covers Java.

Who can join

white-list — true means only players on the whitelist can join. Turn this on for any private server. Manage the list with /whitelist add <name>.

enforce-whitelist — true kicks players who are online but not on the whitelist when the list is reloaded. Useful when you remove someone.

max-players — how many players can be online at once. Default 20. Raising it does not make the server stronger; RAM and CPU decide how many actually fit.

online-mode — true checks every player against Mojang’s login servers. Leave it on. Turning it off lets anyone join with any name, including yours. The only exception is a server behind a proxy like Velocity, where the proxy does the checking.

More in whitelist, OPs and permissions.

How the game plays

gamemode — the default for new players: survival, creative, adventure or spectator.

force-gamemode — true puts players back into the default game mode each time they join.

difficulty — peaceful, easy, normal or hard. Can also be changed in game with /difficulty.

hardcore — true means one life. Dead players become spectators. Best set before the world is created.

pvp — false stops players from hurting each other. Good for friends-only survival.

allow-flight — despite the name, this does not let players fly. It stops the server from kicking players it thinks are flying. Set it to true if you use mods or plugins with jetpacks, elytra boosters or similar, otherwise players get kicked by mistake.

spawn-protection — the radius around spawn where non-OPs cannot build. Default 16. Set it to 0 if you want players to build at spawn.

Newer Minecraft versions have started moving some world rules from server.properties to game rules. If a key is missing from your file, look for a matching setting with /gamerule.

The world itself

level-name — the folder name of the world. Change it to switch worlds or start fresh while keeping the old one.

level-seed — the seed for a new world. Only used when the world is first generated.

level-type — normal, flat, large biomes or amplified. Also only used for new worlds.

To use a new seed or type, change the value and also change level-name (or delete the old world folder after backing it up).

Performance

view-distance — how many chunks around each player are sent to the client. Default 10. Lowering it to 8 is one of the easiest ways to reduce load.

simulation-distance — how many chunks around each player actually tick (mobs move, crops grow, redstone runs). Default 10. Setting it to 6 or 8 saves a lot of CPU while players still see far.

If your server lags, these two are the first settings to try. The full lag guide is fix lag: TPS and MSPT explained.

Look and feel

motd — the text under your server name in the multiplayer list. Supports colour codes with §, for example §aWelcome.

enable-status — false hides the server from the multiplayer list ping. Players can still join, but the list shows no MOTD or player count. Leave it true unless you have a reason.

server-port — the port Java players connect to. Default 25565. On a hosted server, do not change this yourself; the host assigns it.

A good starting setup for friends

white-list=true
enforce-whitelist=true
online-mode=true
difficulty=normal
pvp=false
spawn-protection=0
view-distance=10
simulation-distance=8
motd=Our survival world

Changes that did nothing?

• The server was running while you saved. Stop it, save again, start it.
• You edited the wrong file, for example a copy in a backup folder.
• The setting only applies to new worlds (level-seed, level-type, hardcore).
• A plugin or the world overrides it. Difficulty and game rules can be set per world.

If you want players to join with a nicer address than an IP and port, see custom domains with SRV records.