General game properties.
Determines the server-side viewing distance.
Sets the amount of world data the server sends the client, measured in chunks in each direction of the player (radius, not diameter).
Sets the maximum distance from players that living entities may be located in order to be updated by the server
Measured in chunks in each direction of the player (radius, not diameter).
If entities are outside of this radius, then they will not be ticked by the server nor will they be visible to players.
Determines the side length of the square spawn protection area as 2x+1.
Setting this to 0 disables the spawn protection.
World generation properties.
Determines the world preset/level type that is generated.
Escaping : with \ is required when using a world preset ID, and the vanilla world preset ID's namespace (minecraft:) can be omitted.
For 1.19 and after:
For 1.18 and before:
For 1.15 and before:
Properties related to the whitelist.
Properties related to operators.
Sets the default permission level for ops when using /op. All levels inherit abilities and commands from levels before them.
Properties related to the server connection.
Makes the server appear as online on the server list.
If disabled, it will suppress replies from clients. This means it will appear as offline, but will still accept connections.
Sets the MOTD seen on the multiplayer screen in the Minecraft client.
Pssst. Did you know that you can create your MOTD here?
If the ISP/AS sent from the server is different from the one from Mojang Studios' authentication server, the player is kicked.
Defines the port, query information is sent on.
Unless you have a good reason, this should always be the same as server-port.
Properties for resource packs.
Optional URI to a resource pack. The player may choose to use it.
Note that (in some versions before 1.15.2), the ":" and "=" characters need to be escaped with a backslash (\), e.g. http\://somedomain.com/somepack.zip?someparam\=somevalue
The resource pack may not have a larger file size than 250 MiB (Between 1.17 and 1.15: 100 MiB, Before 1.15: 50 MiB)
Don't touch these, unless you know what your doing.
The maximum number of milliseconds a single tick may take before the server watchdog stops the server. Once this criterion is met, it calls System.exit(1). Setting this to -1 disables the watchdog entirely.
By default it allows packets that are n-1 bytes big to go normally, but a packet of n bytes or more gets compressed down. So, a lower number means more compression but compressing small amounts of bytes might actually end up with a larger result than what went in.
Note: The Ethernet spec requires that packets less than 64 bytes become padded to 64 bytes. Thus, setting a value lower than 64 may not be beneficial. It is also not recommended to exceed the MTU, typically 1500 bytes.
Property descriptions based on content from Minecraft Wiki, which is licensed under CC BY-NC-SA 3.0.