How to ban and unban players on a Minecraft server

Moderation starts with four commands. You need operator rights to use them, see how to op yourself.

The commands

/kick Steve being rude in chat
/ban Steve griefing the spawn
/pardon Steve
/ban-ip 203.0.113.9 spam bots
/pardon-ip 203.0.113.9

kick removes someone for now. They can come straight back.
ban stops a name from joining until it is pardoned. The reason is shown to the player when they try.
pardon lifts a ban.
ban-ip and pardon-ip block an address. Use them rarely: many people share one address (a school, a family, a mobile network) and a VPN gets around it.
/banlist players and /banlist ips show who is banned.

Where bans are stored

In the server folder: banned-players.json and banned-ips.json. You can edit them while the server is stopped, and /pardon only works on names that appear in them. On Saryno, the Players tab lists bans with the reason and date, and lets you ban, kick and pardon with buttons.

Temporary bans and appeals

Vanilla bans are permanent. For a ban that ends after a day or a week, use a plugin such as EssentialsX (/tempban) or LiteBans, see the best plugins. For appeals, give players somewhere to ask: a Discord channel, or a form in your community page.

Online mode and names

On an online-mode server a ban follows the player's account, so changing their name does not get round it. On offline-mode servers the ban is by name and anyone can pick another one, which is one more reason to keep online mode on, see how to whitelist and protect your server.

From in the game

If you linked your Minecraft name to your Saryno account, /saryno manage on your server opens a menu: click a player's head to kick, or right-click to ban, without typing.

A good habit

Write the reason every time. In six months nobody remembers why a player was banned, and the reason is also what the player sees.