A Minecraft dimension of floating islands above a glowing sea.

The Astral Sea is a world beyond the stars: islands float in a golden twilight that never turns into night, and far below them lies the shimmering surface of the sea that gives the dimension its name. Fall off an edge and the sea sends you back to the Overworld, the Nether or the End.

Every biome brings its own blocks, plants and creatures. Most creatures warn you before they attack, so reading their signs is the core skill of the dimension. Further in, dungeons hide guardians that need more than a sharp sword.

In the released pre-alpha (0.1.0-pre-alpha) there is no portal yet. In a world with cheats enabled, the command /astralsea tp takes you into the dimension.

In development: a portal frame of gold blocks, built like a Nether portal and lit with an End Crystal, which fills with the moving surface of the Astral Sea. It is a prototype and not part of any released version yet.

Read about the portal prototype

Each biome has its own palette, terrain and inhabitants, and the dangers grow the further you go. The Astral Highlands are the gentlest place to start.

• Astral HighlandsGolden grass terraces and pale stone floating above the Astral Sea, and for most travellers the first sight of the dimension.
• Astral WetlandsStacked islands of reeds, willows and glowing pools, all fed by Astral Water.
• Shroom VilesA violet fungal wild of giant mushrooms, glowing mycelium and drifting spores.
• Astral ForestA deep forest of six tree species, with moonwells, rivers and hidden treasure caches.
• Golden ForestA shining forest of golden trees, aether vents and clover groves.
• Caustic SlopesToxic terraced slopes of rust-coloured rock, with caustic water, gas fields and geysers.
• Shattered FurnaceA volcanic land of lava rivers, small volcanoes, fire geysers and charred ruins.
• The Fractured HeightsA dark, hostile mountain range of terraces, sharp ridges and needle peaks under an almost black sky.
• Frostveil ExpanseSnow-covered islands with crimson frost trees, ice spires and glowing caves.
• Astral DunesIn developmentSand islands of pale and golden dunes, with palm oases, sinking sand and a ruined temple.

The archive lists 83 creatures in 0.1.0-pre-alpha, with 17 more in development. Grazing herds, skittish birds, ambush hunters and creatures that pass for blocks of sand: each has its own behaviour, and many come in several colour variants. Hit a peaceful creature too often and it may turn into a red, hostile corrupted form.

The bosses guard the deepest places of the dimension: the Astral Colossus in the Hollow Sanctum and the Toad Prince beneath the Wetlands are in the pre-alpha; The Crucible Warden, The Penitent, and Corrupted Penitent are in development.

BossAstral ColossusThe ancient red-black stone guardian at the heart of the Hollow Sanctum, assembled from floating segments around a glowing core.BossToad PrinceA colossal toad waiting in a cave arena beneath the Wetlands, as tough as the Colossus but nothing like it to fight.BossThe Crucible WardenThe guardian of the Molten Heart: a construct of furnace bricks and magma, held together by heat.BossThe PenitentA great spirit in red with a burning candle on its head, waiting in the crypt beneath the tree fortress.BossCorrupted PenitentWhat the Penitent becomes instead of dying: a second, full health bar and nothing left to hold it back.

Browse all creatures in the archive

Dungeons are hand-built places with their own inhabitants and a boss at the bottom. Their rooms teach you the signals you will need for the final fight.

StructureHollow SanctumAn ancient dungeon beneath the Highlands. Its constructs teach you the signals you will need against the Astral Colossus.StructureToad Prince DungeonAn underground dungeon beneath the Wetlands, reached by jumping down a well.StructureThe Crucible DepthsAn abandoned forge-mine deep beneath the Shattered Furnace, where lava still runs through the old channels.StructureTree fortress of the PenitentA library built into five great trees of the Astral Forest, with a crypt sealed deep below the main trunk.

The Astral Sea plays by its own rules. Astral Water pushes you up instead of letting you sink, Spirit Storms turn the sky red and hurt anyone caught in the open, and vanilla tools barely scratch the local stone until you make gear adapted to the dimension.

MechanicAstral WaterThe glowing water of the dimension, which lifts players and animals towards the surface.MechanicSpirit StormsEvery hour or two the sky over the Astral Sea turns red and a Spirit Storm sweeps across the islands.MechanicUniversal CorruptionStrike a peaceful creature again and again, and it may turn into something larger, angrier and glowing red.MechanicAstral AdaptationInside the Astral Sea, gear from the dimension beats vanilla gear. Outside, it is the other way round.MechanicSoul CatcherA device that catches the souls of astral creatures that die nearby.MechanicRunecraftingCarve runes into stone and forge them into swords and armour.

Rune stones can already be carved and set into gear; their effects come in a later version.

The Astral Sea runs on Minecraft Java Edition 1.21.1 with Fabric Loader 0.19.5 or newer, Fabric API and Java 21. Sodium and Iris are optional; shader packs such as Complementary Reimagined and Rethinking Voxels are adjusted for the dimension.

See the full compatibility list

There are three ways in: the Windows installer (sets up Fabric, Fabric API and the mod, with optional Sodium and shaders), the modpack (.mrpack) for the Modrinth App or Prism Launcher, or the mod file on its own for a manual Fabric setup.

The first pre-alpha, 0.1.0-pre-alpha, was released on 2026-10-30. It is unfinished and unbalanced, so back up your worlds before you try it. Everything marked “In development” on this site exists in the mod's development builds but is not part of a released version yet.