Pick Terralith if you want new biomes and structures. Pick Tectonic if you want taller mountains, deeper oceans and larger landmasses. Most readers do not have to choose: Terralith's page calls it fully compatible with the mod of Tectonic, and Tectonic ships a Terralith-compatible setup.
Facts here come from both projects' Modrinth pages and our catalogue entries, read on 9 October 2026. We did not generate worlds or test either project, so statements about how terrain looks are the creators' own.
Terralith and Tectonic at a glance
| Fact | Terralith | Tectonic |
|---|---|---|
| What it changes | Over 95 new biomes, reworked vanilla biomes, custom structures | Terrain shaping: continents, mountain ranges, deeper oceans, canyons, dunes |
| Distributed as | Data pack, plus a separate mod file | Data pack, plus a mod file |
| Newest listed file | Data pack, Fabric and NeoForge 2.6.5+26.3 (2026-09-27). Forge and Quilt 2.5.14 (2025-12-16) | Fabric and NeoForge 3.0.31 for 26.3 (2026-09-27). Data pack 3.0.29 (2026-09-22). Forge 3.0.17 (2025-11-08). Quilt 2.4.4 (2025-02-17) |
| Loaders with mod files | Fabric, NeoForge, Forge and Quilt | Fabric and NeoForge to 26.3, Forge to 1.20.4, Quilt stopped at 1.21.4 |
| Side | Client optional, server required | Client optional, server required |
| Licence label on Modrinth | Stardust Labs License | MIT |
| Modrinth downloads | 23.9M | 16.9M |
What Terralith changes
Terralith
@Apollo · Data Pack
Checked Source and install notes
Terralith adds over 95 biomes, updates almost every vanilla biome, and adds terrain types such as canyons, shattered biomes, floating islands and deep ocean trenches. It also adds structures including the Spire, Fortified Villages and the Glacial Hut, and custom caves such as the Frostfire Caves. Its page says it uses only vanilla blocks.
The mod file has a config (since 2.6.0) with toggles for custom structures, Skylands, fog tweaks and terrain slabs. Its page also lists official add-ons, including one that stops all Terralith structures from generating.
What Tectonic changes
Tectonic
@Apollo · Java Mod
Checked Source and install notes
Tectonic reshapes terrain rather than adding biomes. In v3, terrain forms continent-like landmasses thousands to tens of thousands of blocks wide, with islands of up to around a thousand blocks in the oceans between. Its page lists mountain ranges that approach the build limit, oceans deep enough to reach the deepslate layer, underground rivers, lava tunnels, jungle pillars, canyons, dunes, plateaus, valleys and wetlands.
The mod file adds a config screen and a few extras, such as deeper Ocean Monuments to match the deeper oceans. With Terralith installed, Tectonic's islands spawn Calderas and Volcanoes.
Versions and loaders
Terralith's data pack covers 1.19 to 26.3. Its mod files cover Fabric 1.18.2 to 26.3 and NeoForge 1.20 to 26.3. Forge and Quilt files stop at 1.21.11, while Fabric and NeoForge continue to 26.3. The newest Fabric and NeoForge files require Lithostitched.
Tectonic's data pack covers 1.18.2 to 26.3. Its mod files cover Fabric 1.18.2 to 26.3, NeoForge 1.19.3 to 26.3 and Forge 1.18.2 to 1.20.4. Quilt is stopped, with files ending at 1.21.4. The newest Fabric file requires Fabric API and Lithostitched, and the newest NeoForge file requires Lithostitched.
When to run both
Running both is the setup both pages describe. With Terralith's mod file, use Tectonic's mod file, which ships the Terralith-compatible setup. With Terralith's data pack, Terralith's page says you must use Terratonic instead of Tectonic. Tectonic offers its Terralith-compatible version as a standalone data pack too.
Do not swap between Terralith's data pack and mod file in one world. Since 2.6.0 they differ, and the page warns of potential damage to your world. For file placement, see our guides to installing mods on Java and installing data packs.
Which to choose if you only want one
Choose Terralith for variety: new biomes, structures and caves, plus its own terrain types such as canyons and floating islands. Choose Tectonic for scale: bigger mountains, deeper oceans and continent-sized landmasses. Both pages describe compatibility with biome mods that use Terrablender: Terralith's page says it works with most such mods, and Tectonic's page names Biomes O Plenty, Regions Unexplored and Nature's Spirit. For Terralith against a biome mod, see Terralith vs Biomes O' Plenty.
Trade-offs of each
- Terralith cannot be removed from an existing world, and its page advises against adding it to one. Start a new world.
- Terralith's page says biome-adding data packs are typically not compatible, while most biome mods work through Terrablender or equivalent.
- Tectonic's page says it is not compatible with CliffTree on 1.20, and needs small tweaks on 1.21. The tweaks ship with the mod file.
- Both mods need Lithostitched on their newest Fabric and NeoForge files, and both are required on the server.
- Neither repository shows a licence file in our catalogue. Terralith's Modrinth label is the Stardust Labs License and Tectonic's is MIT.
For the wider split between world generation mods and data packs, read our explainer, or browse popular biome and terrain mods.
