How portals link
When you step through a portal, the game divides your X and Z by 8 (going to the Nether) or multiplies them by 8 (coming back). Y stays the same, limited to the Nether's height. It then looks for an existing portal near that spot.
| Direction | Search area |
|---|---|
| Overworld → Nether | Searches 16 blocks around the target for a portal |
| Nether → Overworld | Searches 128 blocks around the target for a portal |
If it finds none, it builds a new portal as close as it safely can. That's how two Overworld portals end up linking to the same Nether one.
Linking two portals properly
- Stand in your Overworld portal and press F3 to read its X, Y and Z.
- Enter them here to get the Nether coordinates.
- Go through, then walk in the Nether to those exact coordinates and build a portal there, even if one appeared nearby.
- Break the portal that the game made for you if it's in the wrong place.
Portals built at the matching coordinates always link to each other, as long as no other portal is closer to the target.