Spawner & Dungeon Finder for Minecraft

A spawner only works while a player is close to it: within 16 blocks, and in Java that distance is a sphere, so height counts as much as X and Z. Two spawners can share an AFK spot only if some point is within 16 blocks of both, which caps the gap between them at 32 blocks. Real farms want them much closer, to leave room for the kill chamber.

A dungeon is a small cobblestone and mossy cobblestone room with one spawner and up to two chests. In Java, half of all dungeon spawners are zombie spawners, and skeletons and spiders take a quarter each, so mixed pairs are common and matching pairs are rarer. Filter by mob when you want a matching pair, such as two skeleton spawners for bones and arrows.

Witch huts call for a different kind of group. Witches keep spawning inside a swamp hut, so a farm that covers two huts at once doubles the redstone, glowstone and sugar it produces. The catch is distance: one AFK spot has to be within 128 blocks of the spawning space in every hut, because Java never spawns hostile mobs farther from a player than that.

The same tool looks for witch huts in groups on Java seeds. A double hut is the realistic target on a single seed; a true quad is rare enough that finding one means searching many seeds, not one map.