Terralith and Tectonic on Your Minecraft Server: Worlds with New Biomes and Mountains

What each one does

Terralith (by Stardust Labs) adds dozens of new biomes to the Overworld, from canyons and red deserts to cherry forests and volcanoes, made only with vanilla blocks. That's why it works as a datapack and whoever joins sees it with their usual Minecraft.

Tectonic changes the shape of the terrain, not the biomes: long mountain ranges, much taller mountains, wide plains, bigger rivers and caves. It's also a datapack and a mod.

Together: as mods, Terralith and Tectonic are compatible as they are. As datapacks, their authors ask you to use Terratonic instead of both separately: it's a datapack that joins Terralith's biomes with Tectonic's terrain. Putting both in as separate datapacks gives weird terrain.

From the same studio as Terralith there's more for other dimensions and structures (Incendium for the Nether, Nullscape for the End, Structory for structures); they install the same way and can be combined. Read on each one's page whether any of them needs something from players.

Datapack or mod?

On a Paper server (the one we deliver when you create a Minecraft server), datapack: you upload a .zip to the world folder and that's it, and you can keep using your plugins. It's the simplest option and the one this guide explains step by step.

On a modded server (Fabric, Forge or NeoForge) you can use the mod version: it goes in the mods folder and, in Tectonic's case, it has configuration options the datapack doesn't. If the world comes from a modpack that already includes Terralith or Tectonic, don't add them again.

Either way, the version has to match your server. Tectonic says on its page (as of October 2026) that it only fixes bugs on 1.21.1 and 26.1, so check carefully which versions each file offers on Modrinth before downloading it. One for another version may not load, or may generate badly without warning.

Why it has to be a new world

A world generation pack only changes the chunks generated after you add it. What's already explored stays as it was: new biomes don't appear where you've already been.

If you add it to a world in progress, at the border between old and new you'll see cuts: walls hundreds of blocks high, rivers that end dry, a desert stuck to a snowy mountain. With Tectonic it shows more, because the new terrain is much taller than vanilla's.

That's why the authors recommend a new world. If you don't want to start from scratch, the halfway option is to leave the old world as it is and travel far (thousands of blocks) to explore ungenerated terrain, knowing there'll be a cut somewhere.

Installing Terralith (or Terratonic) on a new world, step by step

1. Back up the server

   In the panel, «Backups», create one before touching the world. The free server has no backups: there, set the old world aside as described below and don't delete it.

2. Download the datapack for your version

   On Modrinth, on Terralith's page (or Terratonic's if you want both), choose your server's Minecraft version and the datapack file, not the mod one. It's a .zip: don't unzip it.

3. Stop the server and set the current world aside

   With the server stopped, in «Files» rename the world folder to something like world-before-terralith. If your version has separate world_nether and world_the_end folders (Paper before 26.1), rename them too; since 26.1 they live inside world.

4. Create the new world folder with its datapacks

   Create an empty world folder and, inside it, another one called datapacks. Upload the .zip there. That way the datapack is already in place when the server generates the world for the first time.

5. Choose a seed if you want

   In server.properties, level-seed. Empty means random. With Terralith, the seeds you know from vanilla give different worlds: don't expect the same map (more about seeds).

6. Start it and check

   Press «Start» and wait for it to finish generating (you'll see it in the «Console»). Type /datapack list: the .zip should be among the enabled ones. In game, the debug screen (F3) shows the biome: Terralith's carry their name in front, terralith:…

Performance: pregenerate and watch the RAM

Generating terrain with these packs costs more CPU than vanilla, especially with Tectonic, and the first days of a new world are when it shows most: every player exploring in a different direction forces the server to generate. It's the classic cause of «it stutters when we go far».

The fix is to pregenerate a circle around spawn with Chunky before opening the server to everyone (guide to pregenerating with Chunky). With the world already generated, playing runs as smoothly as vanilla.

A Terralith or Tectonic world also takes a bit more disk because of the varied terrain. Careful on the free server, which has little disk: pregenerate a small radius.

For RAM, the same numbers apply as for a normal Paper server with the same players (RAM guide): what needs more is generation, not having the pack installed.

Removing it or changing your mind

If you delete the datapack from an already generated world, what's explored stays as it is (with Terralith's biomes) and new terrain generates as vanilla, with cuts at the border. At startup, Minecraft may warn that biomes or world settings are missing: if in doubt, restore the backup or go back to your world-before-terralith folder.

To go back to the old world: stop the server, rename the new world folder and give the old one its name back.

Frequently asked questions