Upgrading your server to Minecraft 26.3

26.3 is out

Minecraft 26.3, Wilderness Bound, shipped on 15 September 2026. The release is on the version list with its exact requirements straight from Mojang's manifest, and its compatibility page tracks every server software build the hour a project publishes one.

Two things that matter for the upgrade:

1. Java 25, same as 26.2. The runtime requirement did not change, so there is no separate Java upgrade in this drop. Confirm yours with the Java version checker if you are not sure.
2. Server software builds are arriving. Paper is publishing experimental builds and Purpur already has release builds. Other projects follow at their own pace. The compatibility page is the single place to check who has published what.

Upgrading step by step

The shape is the same as every drop-to-drop upgrade, and the 26.1 to 26.2 guide walks it in more detail.

1. Wait for your server software

Use a build that is not marked experimental, unless you run a test server where experimental is exactly the point. A production server running on experimental builds is the project telling you that you should not.

2. Audit your plugins

Go through plugins/ and sort every jar into three piles:

• Actively maintained, updated quickly last drop. These already have or will have 26.3 builds within days. Nothing to do.
• Maintained, but slow last time. Look at how long their 26.2 build took. That gap is your realistic upgrade date.
• Abandoned. Find the replacement now and run it on 26.2 first, so the 26.3 upgrade gets one moving part shorter.

3. Back up and convert

Copy the world, convert the copy with no plugins loaded, and read the log. The world conversion is one way, on this drop like every other, and a backup you have not restored is a file, not a backup.

4. Add plugins back in groups

Permissions and economy first, then gameplay, then cosmetic. One group at a time, restarting between each, so the log tells you which jar caused a problem.

5. Check the protocol situation

Players on 26.2 will be refused by a 26.3 server unless you run a translation proxy such as ViaVersion. The connection checker gives you the answer to put in your announcement.

The common mistake right now

The first weeks of a drop are when the ecosystem finds its bugs: the first server software builds may still be experimental, plugin authors are still compiling, and the players flooding in bring the exact load that surfaces conversion problems. A production server that updates two weeks after release, onto stable builds and updated plugins, delivers the same 26.3 with none of the breakage.

The compatibility page for 26.3 lists every server build the hour a project publishes one. Check back there rather than refreshing social media.