Getting your server ready for Minecraft 26.3

Where 26.3 stands right now

26.3 is in pre-release. The snapshots ran from late June through August and the pre-releases started in September, which historically means the release itself is weeks away, not months. Every snapshot and pre-release is on the version list with its exact requirements, straight from Mojang's manifest.

Two things are already worth knowing as a server owner:

1. The Java requirement has not moved. The 26.3 pre-releases require Java 25, the same floor as 26.2. Unless that changes at release, there is no runtime work in this upgrade. Confirm it on release day with the Java version checker rather than taking this page's word for it.
2. Server software builds will lag the release by days to weeks. That is normal. Paper publishes experimental builds first and stabilises them later, and the projects that track it follow their own pace. Running a pre-release build in production is the project telling you not to; the waiting is part of the upgrade.

What to do before release day

The work that makes an upgrade slow is never the jar swap. It is the plugin audit, and nothing stops you doing that today.

Go through plugins/ and sort every jar into the same three piles as the 26.2 upgrade:

• Actively maintained, updated quickly last drop. These 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, and it is better to know it now than to discover it with players asking.
• Abandoned. Find the replacement now, run it on 26.2 for a week, and the 26.3 upgrade gets one moving part shorter.

Then check your backup actually restores. 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.

Release day, in order

1. Wait for a build of your server software that is not marked experimental, unless you run a test server where experimental is exactly the point.
2. Copy the world, convert the copy with no plugins loaded, and read the log.
3. Add plugins back in groups, permissions and economy first.
4. Check the protocol situation before announcing: players on 26.2 will probably be refused by a 26.3 server, and the connection checker gives you the answer to put in the announcement.

The 26.1 to 26.2 guide walks each of these steps in detail, and they carry over unchanged: a drop-to-drop upgrade is the same shape every time, which is the good news about the new release cadence.

The one mistake specific to this moment

Do not upgrade the moment the release trends. The first hours of a drop are when the ecosystem finds its bugs: the first server software builds are 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 moment it ships, the release appears on the version list with its Java requirement and downloads, and its compatibility page lists every server build the hour a project publishes one. Check back there rather than refreshing social media.