Update a Java Minecraft server without losing the world: back up, check plugin compatibility, test on a copy, update the jar and know how to roll back.
Why updates are risky
A new Minecraft version converts your world to a newer format the first time it loads. That conversion only goes one way. Once a world has been opened in a newer version, loading it again in an older one can corrupt it. Add plugins that may not be ready on release day, and an unplanned update is one of the most common ways servers break.
Before you touch anything
- Take a full backup of the server folder and any plugin databases, and check that you can open it. See the backup guide.
- Read the update notes for your server software (Paper, Purpur and so on) for breaking changes and required Java versions.
- Check every plugin you run for a version that supports the new Minecraft release. Plugins that are not updated yet are the usual blocker.
- Check which Java version the new Minecraft version needs and install it if necessary.
- Pick a quiet time and tell your players in advance.
Test on a copy first
Copy the whole server folder to a separate directory or machine, start the copy on a different port, and update that one. Join it, walk around old builds, test the main plugins and watch the console for errors. If anything is broken you have learned it without risking the real world.
While you test, change the port in the copy's server.properties and turn on the whitelist so players cannot connect to it by accident.
The real update
- Announce it and stop the server cleanly.
- Back up one more time right now.
- Replace the server jar with the new version for your software.
- Update plugins to the matching versions. Remove plugins that are known to be incompatible and note them so you can add them back later.
- Start the server and read the console from the top. Warnings are normal; red errors on startup are not.
- Join, test permissions, claims, the economy and anything players rely on.
If you want old and new players to connect
You do not have to force every player onto the newest version. Plugins such as ViaVersion let newer clients join an older server, and ViaBackwards and ViaRewind help older ones. See the Via plugins guide. This is the easiest way to update the server without dropping players on release day.
Rolling back
If the update goes wrong, stop the server, put the previous jar and plugins back, and restore the world from the backup you took before updating. Do not just swap the jar back and load the converted world, because it may already be damaged. This is exactly why the pre-update backup matters.
Afterwards
- Update the version on your MCServerShare listing so players can find you by version.
- Keep a note of the plugin versions that work, so the next update is easier.
- Watch the console and the profiler for the first day, in case a problem only appears under load.
Frequently asked questions
Can I downgrade a Minecraft world after updating?
Not safely. A newer version converts the world one way, and loading it in an older version can corrupt it. Always take a backup before updating and restore from it if you need to go back.
How do I update my Minecraft server?
Back up, check plugins support the new version, test on a copy of the server, then stop the server, replace the jar, update plugins and start it while reading the console.
What if my plugins are not updated yet?
Wait for the plugin updates or remove the incompatible ones until they are ready. You can use ViaVersion so newer clients join an older server meanwhile.
Should I update on release day?
Usually it is safer to wait until your server software and key plugins officially support the new version, then test on a copy.