For Creators & Hosts

How to Update a Minecraft Server Without Losing Your World (Java, Bedrock, Aternos, Plugins)

The boring, safe routine: back up, check Java and your plugins, swap the files, and never try to go back.

New Minecraft release, and your friends are already asking when the server's catching up. Here's how to update a Minecraft server without waking up to a wrecked world.

The short version: stop the server, copy your whole server folder somewhere safe, check that you have the Java the new version needs, make sure your plugins or mods have builds for the new version, swap in the new server jar, start it and watch the log. Do it in that order. And don't plan on going back. A world that's been opened in a newer version can't be safely loaded in an older one, so your way back is the backup, not a version switch.

Versions in this guide are as of November 2026: the latest Java Edition release is 26.3 (out September 15, 2026), and 26.4 is in snapshots. Java Edition now uses the 26.x numbering, while Bedrock still uses 1.26.x.

Before you update: the checklist

  1. Back up everything. Not just world. Copy the whole server folder, configs, plugin settings and all, with the server stopped.
  2. Check Java. Run java -version. Minecraft 26.1 and newer needs Java 25. Older releases are different, per the Minecraft Wiki:
    Minecraft versionJava required
    26.1 and newerJava 25
    1.20.5 to 1.21.11Java 21
    1.18 to 1.20.4Java 17
    1.17Java 16
    1.12 to 1.16.5Java 8
    The launcher ships its own Java for the game, but a server runs on whatever Java is installed on the machine. If you're jumping from a 1.21 server to 26.x, you'll need to install a newer Java first. Guides from the 1.21 days will tell you Java 21, and that's now out of date.
  3. Check your plugins or mods. Every one needs a build for the new version. If one doesn't have one yet, wait or drop it.
  4. Tell your players. Once the server updates, everyone's client needs to match.

Updating a vanilla Java server

This is the easy one. If you built yours with my guide to how to make a Minecraft server, you already know the layout.

  1. Stop the server and back up the folder.
  2. Download the new server jar from minecraft.net/en-us/download/server. It's free. Get it there and nowhere else.
  3. Put it in the server folder. Either rename it to match the jar name in your start command, or leave the new name and edit the start command to point at it.
  4. Start it with the same command you always use, for example java -Xmx4G -Xms4G -jar minecraft_server.26.3.jar nogui.
  5. Watch the console. On this first start the server loads your world in the new version, and from then on it's a new-version world. Let it finish loading, and don't kill it halfway.

Your world folder, server.properties and the rest stay where they are, so your settings carry over. My server.properties explainer covers what they do.

Updating a Paper or plugin server

Paper has its own official routine, and the order matters: plugins first, then Paper.

  1. Back up your world folders, server config files, plugin configs and plugin jars. If you pay for hosting, your host may have its own backup and update tools, so check its docs.
  2. Update plugins. Make a folder called update inside plugins, and drop the new plugin jars in it. They get swapped in on the next restart, so plugin and server updates can happen together. Never replace a jar in a running server.
  3. Update Paper. Download the new jar from papermc.io/downloads, stop the server, rename the new file to match the name in your start command, replace the old jar, and start it. Watch the startup log for plugin trouble.

Paper's docs say not to automate this, because auto-installing builds is how plugin conflicts sneak in, and to be around when you update. I agree. Do it when you can watch it. New to plugins? Start with how to install Minecraft server plugins, and if you're still choosing software, the server software comparison has the options.

One caveat: a plugin server can only move as fast as its plugins. If one you rely on has no build for the new version yet, you wait for it or drop it.

Updating a modded server (Fabric, Forge)

The pattern is the same everywhere: install the new loader build made for the new Minecraft version, and swap every mod for a build made for that same version. A single mod without a matching build is enough to hold the whole update back, so check each mod's page before you touch anything. If you're building a pack from scratch, how to make a modded Minecraft server goes through the setup.

Updating a Bedrock Dedicated Server

Bedrock servers don't swap a single jar. You download a fresh zip and move your data across. The current release is 1.26.63.1 as of November 2026, from minecraft.net/en-us/download/server/bedrock (Windows and Ubuntu builds).

  1. Stop the server and back up the whole folder.
  2. Unzip the new version into an empty folder.
  3. Copy across your worlds folder, allowlist.json, permissions.json and server.properties, plus any custom packs you've added.
  4. Start the new server and check that your world loads.

There's no /reload on Bedrock, so every change means a restart. The full setup is in how to make a Minecraft Bedrock server.

Updating an Aternos server

Do the backup first. On Aternos that means linking a Google Drive account (in your account settings or on the server's backups page), adding the backup service to your server with the + button on the backups page, then hitting Create Backup. A backup includes your world, player data, settings and any plugins, mods, add-ons or datapacks. You can also turn on automatic backups when the server stops and cap how many it keeps.

Once that's done, change the version from your server's panel, on the software page. Restoring a backup later replaces your current server files completely, world included, which is exactly what you want if the update goes wrong. If you run mods or plugins, they have to match the new version too. Not sure about the host? I looked at it in is Aternos safe.

Minecraft Realms

You don't update a Realm. Realms update themselves, and you don't get to pick the version. That's the trade for not running anything yourself.

Why you can't go back

Loading a world in an older version than it was last opened in is called downgrading, and it's dangerous. The Minecraft Wiki says it makes the world prone to corruption, data loss or crashes: blocks, items and entities the older version doesn't know get removed, and missing biomes turn into plains. Even updating back up won't undo it. The game itself warns that downgrading isn't supported when you try it in singleplayer.

So if an update goes badly, stop the server, restore the backup you made, and wait for your plugins or mods to catch up. This is why the backup comes first.

When something breaks after the update

How to play on an outdated server

If you're the player and the server is behind, you have two options. The server owner can install ViaVersion, which lets newer clients join older servers. Add ViaBackwards for clients older than the server, and ViaRewind as well if they're on 1.7 or 1.8. It runs best on Paper, and setup is at viaversion.com/setup. Heads up: ViaVersion usually trails a Minecraft release by a few days, so a freshly updated server can briefly lock out older clients.

Or you do it yourself: pick the matching older version in the launcher and play on that.

The routine, in one breath

Stop, back up, check Java, check plugins and mods, swap the files, start it and read the log. Do that every time and updating becomes a routine chore instead of a gamble.