How to Make a Nether Portal in Minecraft

The smallest working portal is a frame 4 blocks wide and 5 blocks tall, which leaves an opening 2 blocks wide and 3 blocks tall in the middle. A full frame uses 14 obsidian, but the four corners do not matter, so you can build it with just 10.

Portals can be bigger, up to 23 by 23 blocks including the frame, but they still need to be a rectangle with no gaps. Bigger portals cost more obsidian and work exactly the same, so most players stick to the small size.

Obsidian can only be mined with a diamond or netherite pickaxe. It takes several seconds per block even with the right tool, and with any other pickaxe the block breaks without dropping anything.

Obsidian forms naturally where flowing water meets a still lava source, so look near lava lakes underground or at the surface. Pour water over a lava pool and the top layer turns to obsidian you can mine. Be careful not to stand on lava blocks while you work.

If you do not have diamonds yet, you can skip mining entirely. With a bucket of water, a bucket of lava and some blocks to use as a mould, you can pour lava into each position of the frame and turn it to obsidian with water, one block at a time. This is often called bucket casting.

It takes practice and some spare dirt or cobblestone to build the mould, but it only needs iron for the buckets. Keep the water away from the lava source you are drawing from, and never pour lava near wood.

While exploring, you may find a ruined portal: a broken obsidian frame with some crying obsidian and netherrack around it, often with a chest of loot. Replace the missing or crying obsidian blocks with normal obsidian to complete the frame. Crying obsidian does not count as part of a working frame.

Use flint and steel on the inside edge of the frame. You craft it from one iron ingot and one flint, and flint comes from breaking gravel. A fire charge works too. When the purple swirl appears, step in and wait a few seconds.

If the portal will not light, the frame is not a complete rectangle, or something is blocking the opening. Check that the inside is empty and that every side of the frame is obsidian.

Wear at least one piece of gold armour, such as gold boots. Piglins, the Nether's most common mob, will attack you if you are not wearing gold. Bring a stack of cobblestone to build bridges and walls, plenty of food, a bow, and a flint and steel in case a ghast's fireball breaks your portal and puts it out.

Two rules save a lot of trips: never place a bed in the Nether, because it explodes when you try to sleep, and write down your portal's coordinates as soon as you arrive so you can find your way home.