How to Install ViaVersion on a Minecraft Server (2026)

To let other Minecraft versions join your server, put the ViaVersion jar in plugins/ on a Paper or Purpur server and restart: players on newer versions can then join. For older clients, add ViaBackwards next to it, and for 1.7 and 1.8 clients add ViaRewind as well. On Fabric, use the ViaFabric mod in mods/ instead. Install it in one place only (the server or the proxy), and update it whenever Minecraft releases a new version.

What you are working with

All of these run on the server only. Players change nothing: they pick whatever version they like in the launcher and join. ViaVersion 5.12.0, from September 2026, supports up to Minecraft 26.3 (ViaVersion on Modrinth).

Here is a common real case. Paper 26.3 is still in beta, so you keep your server on 26.2. A friend updates their launcher to 26.3 and gets "Outdated server!". ViaVersion on your 26.2 server lets them in. The opposite case, a 26.3 server with a friend stuck on 1.21.11, needs ViaBackwards.

Where does ViaVersion go?

ViaVersion's own docs say to choose the proxy or the backends and keep ViaVersion and all its add-ons together in that one place. If you run an anti cheat like GrimAC, it must go on the backends.

Before you start

• Decide which way you need. Newer clients only needs ViaVersion. Older clients needs ViaBackwards too.
• Use the newest release. ViaVersion only knows about Minecraft versions that existed when it was built. A ViaVersion from July 2026 does not know 26.3.
• Back up, as with any new plugin.

Step 1: Install ViaVersion

1. Download the newest ViaVersion from Modrinth, Hangar or GitHub.
2. Stop the server, upload the jar to plugins/, and start it.
3. Check the console for ViaVersion enabling, then run viaversion (or /viaver) to confirm it loaded.

That is enough for newer clients.

Step 2: Add ViaBackwards and ViaRewind (for older clients)

1. Download ViaBackwards in the same version as your ViaVersion (5.12.0 with 5.12.0) and put it in plugins/.
2. Only if you need 1.7 or 1.8 players, add ViaRewind too.
3. Restart.

ViaBackwards runs on servers from 1.10 up to the newest release (ViaBackwards on GitHub).

Step 3: Limit which versions can join (optional)

ViaVersion creates plugins/ViaVersion/config.yml. To refuse very old clients, set block-versions:

block-versions: ["<1.20"]

Restart after editing. This is a good idea when your world relies on newer blocks that old clients cannot see properly.

The gotcha: older clients see a different world

ViaVersion going "up" is clean: a newer client on an older server sees everything correctly. Going "down" with ViaBackwards is a translation, and the old client cannot show things its version never had:

• New blocks and items are swapped for look alikes. A 1.21.11 client on a 26.3 server sees poplar wood as some older wood. Recipes and mobs it does not know may look or behave oddly.
• Clients older than 1.17 cannot see below Y 0. Worlds since 1.18 go down to Y -64. ViaBackwards does not support world heights other than 0 to 256 for those old clients, so deepslate caves and anything built below Y 0 are invisible to them, and they may fall into what looks like the void.
• Inventories can desync for pre 1.17 clients on 1.17+ servers, and some menus, like the smithing table, do not work on old clients.

So, the server's own version is what everyone really plays. Run the server on the version most of your players use, and treat ViaBackwards as a bridge for the stragglers, not as a way to run an old game on a new server.

Common problems

• "Outdated server" after a Minecraft release: your ViaVersion does not know the new version yet. Update ViaVersion (and ViaBackwards to match), then restart. Support usually arrives within days of a release.
• Older players still get "Outdated client": ViaBackwards is missing, or its version does not match ViaVersion.
• ViaBackwards will not enable: ViaVersion is missing or older than it. They must be the same release.
• Strange behaviour behind a proxy: Via is installed on both the proxy and the backends. Remove it from one side.
• Bedrock players still cannot join: ViaVersion is Java to Java only. Bedrock needs Geyser and Floodgate.
• Modded clients cannot join: Via does not translate mods. On Fabric, Forge or NeoForge servers with content mods, everyone needs the exact same versions.

ViaVersion on GamezServers

On a Minecraft server from GamezServers, pick Paper or Fabric in Settings, then use the file manager to download ViaVersion and ViaBackwards from their links straight into plugins/ or mods/. Press Backup first, and when Mojang ships a new version, update the jars the same way. If you would rather move everyone to the new version, see how to update a Minecraft server to a new version, or outdated server and outdated client fixes for the error itself.

FAQ

What is the difference between ViaVersion and ViaBackwards?

ViaVersion lets newer clients join an older server. ViaBackwards, which needs ViaVersion, lets older clients join a newer server.

Do players need to install ViaVersion?

No. It runs on the server only, and players join with a normal launcher on their own version.

Does ViaVersion work on Fabric or Forge servers?

On Fabric, use the ViaFabric mod. Forge and NeoForge servers are not supported, so run mixed versions on Paper or Fabric.

Can ViaVersion let Bedrock players join?

No. ViaVersion only translates between Java versions. Bedrock players need the Geyser and Floodgate plugins.