A Nether Portal Needs Obsidian Blocks Arranged in a Frame, Then Fire

A Nether Portal is a rectangular frame made of obsidian blocks that opens a doorway to the Nether dimension. You build it by placing obsidian in a 4-by-5 pattern (the frame itself, not filled in), then lighting it with fire or flint and steel. The portal activates when ready once you ignite the center blocks, and you can walk through to reach the Nether.

The easiest way to get obsidian is to find lava and pour water on it. Lava occurs naturally in caves, ravines, and the Nether itself. When water touches lava, it hardens into obsidian. You will need a diamond or netherite pickaxe to mine it — stone and iron pickaxes will not break it. Once you have 10 obsidian blocks, you can build the portal in your base or anywhere else on the Overworld.

Key Takeaways

  • Obsidian forms when water touches lava, and you must use a diamond or netherite pickaxe to collect it.
  • The portal frame is 4 blocks wide and 5 blocks tall, with the corners left empty so you can walk through the center.
  • Light the frame with flint and steel or a fire block to set up the purple portal effect.
  • You can build a portal anywhere in the Overworld, and it will connect to a corresponding location in the Nether.

Finding and Mining Obsidian

The fastest way to collect obsidian is to find a lava pool and freeze it with water. Dig down to Y-level 0 to 64 (shown in your debug screen on Java Edition, or in the coordinates display on Bedrock) where lava is common. When you find lava, place water blocks around it or pour water from a bucket onto the lava surface. The lava will turn into obsidian when ready.

Mine the obsidian with a diamond pickaxe (or netherite, which is stronger). Each block takes about 10 seconds to break. You need 10 blocks total: 14 for the frame itself, but the corners are empty, so you only place 10. Collect a few extra in case you make a mistake or want to build a second portal later.

If you do not have a diamond pickaxe yet, you can find obsidian in the End dimension (the black blocks around the exit portal) or in the Nether itself. Both require you to already have access to those dimensions, so the lava-freezing method is the true starting point.

Building the Frame in the Right Shape

The portal frame is 4 blocks wide and 5 blocks tall. Place obsidian in this pattern: a rectangle with the corners and center left empty. The easiest way is to build it on flat ground. Place a row of 4 obsidian blocks, then stack 3 more rows of 4 on top of it, then add one final row of 4. You now have a solid 4-by-5 rectangle. Remove the 4 corner blocks and the 6 center blocks (the 2-by-3 space in the middle). You are left with a frame that looks like a doorway.

The exact layout is: the top and bottom rows are completely filled (4 blocks each). The two middle rows have obsidian only on the left and right edges, leaving 2 empty spaces in the center of each row. This creates the opening you walk through. The portal does not care which direction it faces — north, south, east, or west all work the same way.

Lighting the Portal with Fire or Flint and Steel

Once the frame is built, you need to ignite the center. Use either flint and steel (crafted from 1 flint and 1 iron ingot) or place a fire block in the center. Flint and steel is faster: right-click (or use the secondary action button) on any of the empty center blocks while holding flint and steel. The portal will light up with purple and blue swirling effects.

If you use fire instead, place a fire block in the center by using a fire charge or by lighting wood on fire and letting it spread. Fire works but is slower and less reliable. Flint and steel is the standard method because you control exactly when the portal activates.

The portal stays lit permanently once activated. You do not need to relight it. If the frame is destroyed, the portal closes, but you can rebuild it and light it again.

Understanding Portal Linking and Coordinates

When you build a portal in the Overworld and step through, you arrive in the Nether at a location that corresponds to your Overworld coordinates, but divided by 8. If your Overworld portal is at coordinates X: 400, Z: 400, you will spawn near X: 50, Z: 50 in the Nether. This 8-to-1 ratio means traveling 800 blocks in the Overworld is the same as traveling 100 blocks in the Nether.

If no portal exists at the Nether location where you arrive, the game creates a new one for you. If a portal already exists nearby, you spawn at that one instead. This is why players often build Nether portals in specific locations — to create shortcuts between distant Overworld bases.

When you return to the Overworld by stepping through the Nether portal, you arrive back at your original Overworld portal (or very close to it). The two portals are linked as long as both exist.

What to Bring and What to Expect in the Nether

The Nether is dangerous. Bring armor, a sword, a pickaxe, and food. The Nether has no water (it evaporates), so do not rely on water for defense or travel. Bring a bucket of water anyway — it is useful for climbing and for putting out fires on yourself. Bring blocks to build bridges and escape routes.

Hostile mobs spawn constantly in the Nether: Ghasts (flying creatures that shoot fireballs), Blazes (fire mobs that drop blaze rods), Piglins (hostile unless you wear gold armor), and Hoglins (aggressive boar-like creatures). The terrain is made of netherrack, soul sand, and lava. Lava is everywhere, so watch your step.

Your first trip should be short: step through, look around, and come back. Once you are comfortable, you can explore for resources like nether quartz, ancient debris (for netherite), and blaze rods (for brewing potions).

Troubleshooting Portal Problems

If the portal does not light, check that the frame is complete and the corners are empty. A single missing obsidian block or a filled corner will prevent set up. Rebuild the frame if you are unsure.

If you light the portal but nothing happens, make sure you are using flint and steel or a fire block on one of the empty center spaces, not on the obsidian itself. The fire must be inside the frame opening.

If you step through and do not arrive where you expect, check your coordinates. The Nether location is your Overworld coordinates divided by 8. If you built your Overworld portal at X: 0, Z: 0, you will arrive near X: 0, Z: 0 in the Nether (the division rounds down). If a portal already exists at that Nether location, you spawn there instead of creating a new one.

If the portal closes or breaks, rebuild the frame and light it again. Portals can be destroyed by explosions or by removing obsidian blocks. The portal itself (the purple effect) will vanish, but you can always rebuild it.

Frequently Asked Questions

How many obsidian blocks do I actually need?

You need 10 obsidian blocks for the frame. The 4-by-5 rectangle has 14 perimeter blocks, but the 4 corners are empty, so you place 10. Collect a few extra in case you make mistakes or want to build additional portals.

Can I build a portal in the Nether to return to the Overworld?

Yes. A portal in the Nether works the same way as one in the Overworld. When you step through a Nether portal, you arrive at the corresponding Overworld location (your Nether coordinates multiplied by 8). You can build portals in both dimensions to create fast travel routes.

What happens if I destroy my Overworld portal after going to the Nether?

You will be stuck in the Nether until you build a new portal there. The Nether portal you arrived at will still exist and will take you to a new location in the Overworld (or to an existing portal if one is nearby). Always keep a way back before destroying portals.

Do I need diamonds to build a portal?

You need a diamond pickaxe to mine obsidian, but not to build the portal itself. Once you have the obsidian blocks, you can build the frame with any tools or no tools at all. The pickaxe is only for collecting the obsidian from lava.

Can I move a portal by rebuilding it somewhere else?

Yes. Build a new portal frame in a different location and light it. The new portal will link to a different Nether location based on its coordinates. Your old portal still exists if you did not destroy it, so you will have two portals in the Overworld linking to two different Nether locations.