Seeder - Minecraft seed map, finder & explorer

A seed is the number Minecraft starts from when it generates a world: the same seed on the same version always gives the same terrain, biomes and structures. You can type one when you create a world, as a number or as text, which the game turns into a number (Seeder does the same). In a world you already play, the /seed command shows it.

For biomes, yes. Seeder reproduces Java Edition's world generation, and from 1.18 a seed gives the same terrain and biomes on Bedrock, so the biome map works for Bedrock worlds too. Structures, strongholds and slime chunks are placed differently on Bedrock, so those markers only hold for Java.

In your browser. The world generation comes from cubiomes, a C library compiled to WebAssembly, and runs on every core of your device. Nothing you type is uploaded! Searches use a lot of CPU, so your device may slow down while one runs.

Java Edition from Beta 1.7 to 26.3. Pick the version your world was created with: world generation changes between versions, so the same seed can look different on another one.

Since 1.18, Minecraft builds biomes from 3-D noise instead of the old 2-D layers, which makes checking a seed for a biome about a hundred times more expensive: within 300 blocks, one core checks about a dozen seeds per second. Keep the biome range small, or better, add a structure: only seeds that already have it get their biomes checked.

Nothing leaves your browser! Google Analytics counts visits and Google AdSense shows ads, but that's it, everything else is done in your browser. Donations through the buttons at the bottom of the page help pay for it, and the About page tells the rest.