What Protocol Version Is Minecraft 26.3?

Minecraft Java Edition 26.3 uses protocol version 777. That's the number a client and a server compare when you connect, and because 26.2 used 776, a 26.2 client can't join a 26.3 server (or the other way round) unless the server has a translation plugin installed. 26.3 is the Wilderness Bound drop, released on September 15, 2026, and if you were actually after the world-format number, its data version is 5023.

What the protocol number actually does

When you press Join Server, the first packet your client sends is a handshake, and one of the fields in it is your protocol number. A vanilla server checks that number against its own. If they match, the login carries on; if they don't, the server disconnects you on the spot, before any world data has been sent.

It's an exact-match check, not a minimum. A 26.3 client on 777 isn't "new enough" to get onto a 26.2 server on 776, because the numbers simply differ, and the same is true going the other way. Mojang bumps the number whenever a release changes what gets sent over the wire, and every drop so far has, so each one has ended up with its own.

The name on your title screen, "26.3", is the version for people. The protocol number is the one software goes by, which makes it the useful one when you're configuring a proxy or reading a ping response.

The 26.x line at a glance

Version	Released	Protocol	Data version	Resource pack	Data pack	Java
26.1	March 24, 2026	775	4786	84.0	101.1	25
26.1.1	April 1, 2026	775	4788	84.0	101.1	25
26.1.2	April 9, 2026	775	4790	84.0	101.1	25
26.2	June 16, 2026	776	4903	88.0	107.1	25
26.3	September 15, 2026	777	5023	97.1	121.0	25

The two 26.1 hotfixes kept 775 even though their data version moved, which is why a hotfix doesn't usually split players the way a drop does. Java didn't change this time either: 26.3 still runs on Java 25 like 26.2 and 26.1, so a machine that hosted 26.2 doesn't need a new runtime. Of the two pack formats, the data pack number jumped the most, from 107.1 to 121.0 (the resource pack went from 88.0 to 97.1), and that matches a long list of breaking data pack changes in this drop. The 26.2 vs 26.3 guide for server owners goes through those, and the same breakdown for the previous drop is in what protocol version 26.2 uses.

Is there a 26.3.1 yet?

No. As of September 18, 2026, Mojang's version manifest lists 26.3 as the latest release, and no 26.3.x hotfix is out or announced. If one does come, 26.1's hotfixes suggest it would probably stay on 777, but that's a pattern rather than a rule, so check the number when it lands instead of assuming.

Bedrock numbers are a separate series

Bedrock got Wilderness Bound on the same day, but as Bedrock 26.50, followed quickly by a 26.51 hotfix. There is no Bedrock "26.3" (Bedrock 26.30 is an earlier, unrelated Bedrock release). Bedrock's protocol numbers belong to their own series too: 26.51 reports protocol 2193, and Geyser treats 26.50 and 26.51 as the same 2193. That has nothing to do with 777, and the two can't be compared. A Java server never reads a Bedrock handshake at all, which is why Bedrock players only reach a Java server through a bridge like Geyser (what Geyser and Floodgate are explains the setup).

So if a config file or a tool asks for "the 26.3 protocol", it wants 777. 2193 only belongs in Bedrock-side settings, and a Bedrock server is usually on port 19132 rather than Java's 25565, which is a handy sanity check when a crossplay setup starts to blur together.

What a mismatch looks like to a player

On a 26.2 client, a 26.3 server in the Multiplayer list gets an incompatible icon and the status "Incompatible version!", along with the version name the server reports. What you see if you try to join anyway depends on the server software. Most public servers run Paper or Spigot, which use their own messages: a 26.2 player on a 26.3 server gets "Outdated client! Please use 26.3", and a 26.3 player on a 26.2 server gets "Outdated server! I'm still on 26.2". Owners can reword both in spigot.yml, so some servers show their own text here instead. A vanilla or Fabric server uses Mojang's wording, "Incompatible client! Please use 26.3" (or "Please use 26.2" the other way round), and that one says "client" even when it's the server that's behind.

Whichever of these defaults you get, the version at the end comes from the server, so it tells you exactly which release to switch to. None of these messages means the server is down or that your connection is broken. The versions just don't match. If you're stuck on this right after updating, why you can't join a server after updating to 26.3 walks through the fixes, from making a 26.2 installation in the launcher to picking a server that has already moved over.

How server owners use 777

The first place the number matters is the proxy. Velocity and BungeeCord read each player's protocol number before handing them to a backend, so the proxy has to know 777 exists. Velocity 4.2.0, a stable release from September 14, 2026, maps 777 to 26.3, and SpigotMC announced BungeeCord builds for 26.3 on release day. A proxy build from before 26.3 doesn't know the number, so update the proxy first rather than last.

The second is translation. ViaVersion lets newer clients onto an older server, and ViaBackwards, which runs on top of ViaVersion, lets older clients onto a newer one. A server that moves to 26.3 and still wants its 26.2 players therefore needs both. As of September 18, 2026, the newest public ViaVersion release is 5.11.0, which supports up to 26.2; a maintainer said on September 16 that the finished 26.3 support would go public that day, but it hadn't appeared when this was written. ViaVersion's GitHub releases page, or its Modrinth or Hangar listing, will show whether a 26.3 build is out by the time you read this.

Crossplay servers have one more thing to check. As of September 18, 2026, Geyser supports Bedrock 26.30 through 26.51 but only Java 26.2 on the server side, so no released Geyser build supports a 26.3 Java server yet (only experimental preview builds that aren't meant for production); geysermc.org's supported-versions page is the one to check.

How to check which protocol a server reports

For the vanilla server, the number is inside the jar itself. The official 26.3 server.jar carries a version.json with "protocol_version": 777 alongside the data version and pack formats, which is handy if you've got a folder full of jars and can't remember which is which.

For a running server, the server list ping tells you. Every Java server answers a status request with a bit of JSON, and the version part of a vanilla 26.3 reply looks like this:

"version": { "name": "26.3", "protocol": 777 }

That's what your Multiplayer screen reads to decide whether to mark a server as incompatible, and server-list sites read the same reply. We read the protocol number each server reports, and the 26.3 server list is a quick way to see who's already running the new drop (the 26.2 list is still there for everyone else).

Trust the number over the name. The name is free text that server software and proxies can fill with almost anything, like a network's brand or a range of supported versions. The ping also has room for only one protocol number, so a server behind a proxy or running ViaVersion may accept several versions while reporting just one of them.

FAQ

My ping tool says a 26.3 server is on an unknown version. Is the server wrong?

Almost certainly not. Many pingers and libraries keep their own table that turns protocol numbers into version names, and one that hasn't been updated for 26.3 won't have an entry for 777. The server is reporting the right number; the tool just can't name it yet. Updating the tool, or adding 777 → 26.3 to its table yourself, fixes it.

Can I just change the protocol number so 26.2 players get in?

Faking the number only gets a client past the first check. After that the client and server still send packets in two different formats, so the session breaks down with errors or a disconnect. Translating between those formats is exactly the job ViaVersion and ViaBackwards do, which is why they're the only real fix for mixed versions.

Is the data version the same kind of thing as the protocol version?

No. The data version, 5023 for 26.3, is stamped into world files so the game knows how old saved data is and how to upgrade it when you load an older world. It isn't part of the connection check. 26.3 also started keeping a version_history list of earlier data versions in level.dat, so an upgraded world now records which versions it has passed through.

Both of us are on 26.3 and I still can't join a new server. Why?

Then it isn't the protocol. A fresh 26.3 server now has white-list set to true by default in server.properties, so everyone who isn't whitelisted (or an operator) gets "You are not white-listed on this server!" until the owner adds them or switches the whitelist off.