Minecraft 26.3 on your server: what changed and how to update
26.3 came out on 15 September 2026 as the Wilderness Bound drop: a new autumn biome, a new wood, a new structure and 91 new blocks. For a server owner the headline is quieter. Java stays at 25, clients have to match exactly, data packs move to a new format, and the plugin world is still catching up. This page is what changes on a server, in numbers, and when it makes sense to move.
The short answer
Java
26.3 runs on Java 25, the same as 26.1 and 26.2. Coming from 1.21, the runtime has to move up.
Players
Clients have to be on 26.3 exactly (protocol 777). A 26.2 client cannot join without ViaVersion.
Your world
Upgrades on first start and never goes back down. Take a backup before you change the version.
Vanilla and Fabric servers can update today. On Paper, every 26.3 build was still in the alpha channel on 27 September 2026. Crossplay servers stay on 26.2 until Geyser, which lets Bedrock players in, supports 26.3.
26.3 next to 26.2, number by number
The figures a server owner runs into, side by side with the release before it. The protocol and the world version are the two that decide who can join and whether you can go back.
| 26.2 | 26.3 | |
|---|---|---|
 Release date | 26.2 on 16 June 2026 | 15 September 2026, as the Wilderness Bound drop |
 Java | Java 25 | Java 25, unchanged |
| Network protocol | 776 | 777, so only 26.3 clients can join |
| Data pack format | 107.1 | 121.0, a new major number |
| Resource pack format | 88.0 | 97.1 |
| World version | 4903 | 5023, a world opened in 26.3 does not open in 26.2 again |
 Blocks | 1184 | 1275, 91 new |
 Items | 531 | 574, 43 new |
 Entity types | 164 | 167: the cushion and two poplar boats |
 Recipes | 1585 | 2042, 457 new |
| Game rules | 63 | 63, none added and none removed |
| Server download | 60.9 MB | 62.3 MB |
What is new in 26.3
Most of it lives in the world rather than in the server, but three things matter for how you run one: the new biome and camp only appear in new terrain, the straw bed never touches spawn points, and the cushion is an entity, so a room full of them counts towards the entities in that chunk.
| Addition | What it is |
|---|---|
 Dappled forestBiome | An autumn forest near cold biomes, with poplar trees in red, orange and yellow, red shrubs, leaf litter and shelf mushrooms. Sheep, chickens, cows, pigs, rabbits and foxes spawn in their cold variants. |
 Poplar wood set27 blocks | Logs, planks, stairs, slabs, doors, trapdoors, fences, signs, a shelf, three colours of leaves and a sapling that grows into any of the three. Poplar logs and saplings are also sold by the wandering trader. |
 Red shrubBlock | A small bush that spreads to a neighbouring block with bone meal and goes into a composter. |
 Shelf mushroomBlock, two sizes | Grows on poplar trees and bounces whatever lands on it, like a bed. It goes into mushroom, suspicious and rabbit stew. |
 Straw bedBlock, single use | Skips the night once and breaks. It never resets the spawn point, villagers ignore it, and in the Nether or the End it is destroyed without dropping. Three hay bales make four. |
 CushionEntity, 16 colours | Something to sit on, placed on any flat surface. It is an entity rather than a block, has no collision and is crafted from the matching wool slab. |
 Wool stairs and slabs32 blocks | All sixteen colours, and they dampen sound the way wool and carpet do. |
 Concrete stairs and slabs32 blocks | All sixteen colours, from a crafting table or a stonecutter. |
| Abandoned campStructure, 18 biomes | A camp with a look of its own per biome, with barrels, a common chest and a secret chest. The secret chest can hold iron gear, diamonds, gold and potions. |
 Explorer mapsItems | Maps to other abandoned camps, and new maps to ancient cities, mineshafts, desert pyramids and warm ocean ruins, all found in camp chests. |
 Poplar boatTwo entities | A boat and a boat with a chest, from poplar planks. |
| /compute and /posteffectCommands | /compute works out a number in a block, entity or plain context. /posteffect adds a screen effect to a player, but the effect lives in the resource pack on their side, so the server cannot tell whether it was really shown. |
Should you update your server yet?
It depends on what runs on top of the game. The version number is the easy part; the software you run it with decides the date. This is where each of them stood on 27 September 2026.
| Server type | Where it stands on 26.3 |
|---|---|
| VanillaReady | Released on 15 September. Change the version and restart. |
| FabricLoader ready | The loader lists 26.3 as stable. Whether your server starts depends on each mod having a 26.3 build, so check the mods, not the loader. |
| Paper and PurpurAlpha | 47 builds for 26.3 on 27 September 2026, every one of them in the alpha channel. Fine for a test copy, too early for a server people depend on. Most plugins also need their own update first. |
| NeoForgeBeta | 26.3 builds exist, all marked beta. A modpack stays on the version its makers built it for, so a pack for 1.21.1 should stay on 1.21.1. |
| Crossplay (Geyser)Not yet | Geyser, the bridge that lets Bedrock players onto a Java server, spoke Java 26.2 on 27 September 2026, and on a newer server it does not start. A crossplay server here stays on 26.2 until Geyser supports 26.3: the panel does not accept 26.3 on a crossplay plan, and a server left on latest stays on the newest version Geyser speaks. |
If you are not sure, the safe order is always the same: a vanilla or Fabric server can go now, a plugin server waits until Paper leaves alpha and your plugins have caught up, a modpack stays where its makers put it, and a crossplay server waits for Geyser. Comparing the types themselves is on the server types page.
How to update your server to 26.3
Take a backup first
A world that has been opened in 26.3 is upgraded to the new world version and cannot be opened in 26.2 again. The backup is your way back, and it is the only one.
Check your plugins, mods and data packs
Every plugin and mod needs a build for 26.3. Data packs move to format 121.0, and any pack that changes caves or canyons has to be updated for the renamed carver format before it loads.
Type 26.3 in the version field on Settings
Save from the bar at the bottom. The Java runtime moves with the version by itself, and for 26.3 that is Java 25.
Restart and watch the console
The first start downloads the new files and upgrades the world, so it takes longer than usual. Let it finish: stopping a server in the middle of a world upgrade is how chunks get lost.
Stuck on a message in the console afterwards? The AI Copilot in the panel reads the log with you and says which plugin or mod is behind, and a restore with the version field set back to 26.2 returns you to where you were.
Questions about Minecraft 26.3 on a server
When did Minecraft 26.3 come out?
On 15 September 2026, as the Wilderness Bound drop. It adds the dappled forest, the poplar wood set, the abandoned camp, straw beds, cushions, and stairs and slabs for wool and concrete. Before it came three pre-releases and three release candidates, starting on 1 September.
Which Java version does a 26.3 server need?
Java 25, the same as 26.1 and 26.2. On a runtime that is too old the server refuses to start and names the requirement in the console. On our servers the runtime follows the version you type, so there is nothing to pick.
Can players on 26.2 join a 26.3 server?
Not on a vanilla server. 26.3 speaks protocol 777 and 26.2 speaks 776, and the server turns away any client that does not match. On Paper, ViaVersion lets newer and older clients in, but it cannot give an older client blocks it does not know, so a 26.2 player sees stand-ins for the new ones.
Can I go back to 26.2 after updating?
Only from a backup. Opening a world in 26.3 moves it from world version 4903 to 5023, and an older server will not load a newer world. That is why the backup comes before the version change, not after the first problem.
Do I need a new world to get the dappled forest?
No, but you do need new terrain. Biomes and structures are placed when a chunk is generated, so the land players have already walked through stays as it was. The dappled forest and the abandoned camps show up in chunks generated after the update, which on an old map means exploring further out or generating the edge ahead of time.
Is Paper ready for 26.3?
Not for a live server yet. On 27 September 2026 Paper had 47 builds for 26.3 and all of them were in the alpha channel. That is the moment to try your plugins on a copy, not to move a server your players depend on.
Will my data packs still work?
Most need an update. The data pack format jumps from 107.1 to 121.0, and cave and canyon carvers moved to a new registry with a different format. A world generation pack that changes those will not load until its makers ship a 26.3 version.
Can a crossplay server run 26.3?
Not yet. Geyser, which lets Bedrock players onto a Java server, spoke Java 26.2 on 27 September 2026, and on a newer server it does not start, so nobody gets in over Bedrock and Floodgate can lock Java players out as well. A crossplay server here therefore stays on 26.2: the panel does not accept 26.3 on a crossplay plan, and a server left on latest stays on the newest version Geyser speaks. Once Geyser supports 26.3, so can your server.
Does 26.3 make my server faster?
It generates terrain faster and finds structures faster, according to the release notes. That helps most where a server spends its time making new chunks, like a fresh world or pre-generating a border. On a world that is already explored you will notice little.
Run 26.3 on your own server
Every plan here runs 26.3 today, crossplay plans excepted until Geyser supports it, with Java 25 picked for you, nightly backups to fall back on and the version one field on the Settings tab. The same goes for 26.2 and 1.21.11, if you would rather wait.
Change your Minecraft version How the nightly backups work Paper Fabric How to reduce lag Answer six questions and get one plan View plans and prices
Checked against Java Edition 26.2 and 26.3, 27 September 2026.
Written and checked by the Astroworld Hosting team. Last reviewed on 27 September 2026.
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