A Nether portal is a frame of obsidian, 4 blocks wide and 5 tall, lit with fire. It takes 10 obsidian, because the 4 corners don't have to be obsidian, or 14 with them. No diamond pickaxe to mine obsidian? You can make it in place, with lava and water.
Everything below is Minecraft 26.3, from the Minecraft Wiki, and checked in the game's own files for the recipes and the ruined portal chest.
How to build it
- Put 2 obsidian side by side on the ground.
- Put any block at each end of that row: the corners can be dirt, which you break afterwards.
- Stack 3 obsidian on each corner block: these are the sides.
- Put a block on top of each side, then 2 obsidian between them.
- Light the inside with a Flint and Steel (an iron ingot and a flint) or a Fire Charge. Light it last: fire placed before the frame is complete doesn't open it.
The purple portal fills the 2×3 hole. Stand in it for 4 seconds to travel, or an instant in Creative mode.
How much obsidian you need
| Portal |
Obsidian |
| Smallest, without corners |
10 |
| Smallest, with corners |
14 |
| Largest, without corners |
84 |
| Largest, with corners |
88 |
The smallest frame is 4×5, around a 2×3 hole; the largest is 23×23, around a 21×21 hole. For any size, count twice the hole's width plus twice its height, plus 4 if the corners are obsidian too.
Without a diamond pickaxe
Obsidian can only be mined with a Diamond Pickaxe or a Netherite Pickaxe: any other tool breaks it slowly and gets nothing. But obsidian forms wherever water flows over a lava source, so the frame can be cast in place:
- Build a mold of ordinary blocks, with a hole wherever the frame needs obsidian.
- Pour lava into a hole from a Lava Bucket, then pour water so it flows over the lava: the lava turns into obsidian.
- Pick the water back up with the bucket, and go on to the next hole.
- When the 10 blocks are done, break the mold and light the portal.
Next to a lava pool, one empty Bucket and one Water Bucket are enough: scoop lava from the pool for each hole.
Ruined portals: a head start
Ruined portals are broken frames found across the world, in the Overworld and in the Nether. Some are nearly complete, and their chest can hold obsidian, a Flint and Steel or a Fire Charge. Crying Obsidian in a frame keeps it from lighting: replace it with regular obsidian. Our Ruined Portal Finder shows where they are in your seed.
Where the portal leads
The Nether is 8 times smaller than the Overworld across: going in divides X and Z by 8, coming back multiplies them by 8, and Y stays the same. The game then looks for a lit portal near that spot: within 128 blocks in the Overworld, and within 16 in the Nether in Java Edition (128 in Bedrock Edition). If there is none, it builds a new 4×5 portal close by.
So to link two portals on purpose, build the second one at the matching coordinates. Our Nether calculator gives them both ways.
Good to know
- Zombified Piglins can spawn by a portal in the Overworld, twice as often on Normal as on Easy and three times as often on Hard: wall it in, which also keeps wandering monsters from going through.
- A Ghast's fireball can switch off a portal in the Nether. The obsidian survives it, so relight the portal with your Flint and Steel, and always carry one.
- A Nether portal can't be lit in the End.
