Changing the Minecraft version

Upgrade or downgrade your vanilla Minecraft server in a couple of clicks.

#Changing the version

Server dashboard → Settings → Game version → pick a new version. Save and restart. The new server jar downloads and the server comes back on it.

Take a backup first. Not because the change is risky in itself, but because the world conversion that follows is one-way, and a backup is the only route back.

#What happens to your world

Changing the version does not delete anything. It swaps the server software, and the new version converts the world data the first time it loads it.

That conversion only runs forwards. Minecraft has upgraded world formats through most of its life, and each upgrade assumes the world came from an older version, never a newer one. So:

• Upgrading usually works. New chunks generate in the new format, old chunks are converted on load. Chunk borders where old and new generation meet can look abrupt, which is cosmetic rather than broken.
• Downgrading usually does not. Chunks written by a newer version contain blocks and data the older version has never heard of. Best case it drops what it does not recognise; worst case the chunk fails to load and takes your base with it.

We warn you before applying a downgrade. The warning is not a formality.

#Version jumps worth knowing about

Some upgrades are more eventful than others:

• 1.12.2 to 1.13: the Flattening. Block IDs changed shape entirely. Almost nothing survives this jump cleanly, and no plugin or mod written for 1.12.2 will run afterwards.
• 1.17 to 1.18: world height changed. Existing chunks keep the old height and new chunks use the new one, which produces a visible seam and a strip of odd terrain along the boundary.
• 1.20.4 to 1.20.5: the item component rewrite. Anything that touches item NBT needs updating.

Between minor versions inside the same major release, upgrades are usually uneventful.

#Plugins and mods do not come along for free

Plugins and mods are built against a specific Minecraft version. After a version change, expect to update every one of them before the server starts cleanly.

Do this in the right order: change the version, start the server once with no plugins or mods to confirm the base server and world are healthy, then add things back. Diagnosing a version change and a broken plugin at the same time is twice the work and half the certainty.

#Modded servers

For modded servers, the Minecraft version is baked into the pack. Change the version by re-installing the pack at the version you want from the Modpack tab rather than changing the version directly. A pack built for 1.20.1 does not become a 1.21 pack because you changed the server jar underneath it; it becomes a server that does not start.

If you want the same pack on a newer Minecraft version, check whether the pack author has published one. Many kitchen-sink packs release as separate packs per Minecraft version rather than updating in place, and world transfer between them is rarely supported.

#After the change

Check three things before you tell everyone it is done:

1. The server reached "Done" in the console without errors.
2. You can join and your spawn area looks right.
3. Your plugins or mods loaded, which the console lists at startup.

If any of the three is wrong, restore the backup and try again with fewer variables.

Written and maintained by the Hostd engineering team. Last updated 2026-08-05. Notice a mistake? Tell us.