A Nether Portal Needs Obsidian Blocks Arranged in a Specific Frame

A Nether Portal is a rectangular frame made of obsidian — a dark purple block that only forms when water meets lava. The frame itself is 4 blocks wide and 5 blocks tall on the inside (meaning the obsidian border is 6 blocks wide and 7 blocks tall if you count the frame). You do not need to fill in the center — the purple swirling gateway appears automatically once the frame is complete and you light it with flint and steel.

The minimum obsidian you need is 10 blocks: four on the bottom, four on the top, and one on each side. You can build the frame larger — up to 23 blocks wide and 23 blocks tall — but the standard size works fine and uses less material.

Key Takeaways

  • Obsidian forms naturally where water and lava meet, or you can mine it with a diamond or netherite pickaxe from existing blocks.
  • The frame must be at least 4 blocks wide and 5 blocks tall on the inside, with obsidian forming the border.
  • Light the inside of the frame with flint and steel to set up the portal — the purple gateway will appear when ready.
  • Portals work both ways: stepping into one in the Overworld takes you to the Nether, and stepping into one in the Nether takes you back.
  • You can build a portal anywhere, but placing it near your base makes travel between worlds easier to manage.

Finding or Creating Obsidian

Obsidian appears naturally in the Overworld where water flows over lava. The easiest place to find it is near lava lakes — dig down to lava level (around Y-coordinate 10 to 20 in newer versions), locate a lava pool, and pour water over it from above or the side. The lava will turn into obsidian blocks where the water touches it.

If you want to gather existing obsidian, you need a diamond pickaxe or better (netherite pickaxe is stronger but rarer). A stone or iron pickaxe will not work — the obsidian will break but you will not collect it. Once you have the pickaxe, mine the obsidian blocks and collect them in your inventory.

Mining obsidian is slow — each block takes about 10 seconds with a diamond pickaxe. Gather more than you think you need, because you may want to build additional portals or repair one if it breaks.

Building the Frame in the Right Shape

Place your obsidian blocks in a rectangular outline. The standard size is 4 blocks wide and 5 blocks tall measured on the inside (the space you will fill with the portal). This means you are placing obsidian in a shape that looks like a picture frame when viewed from the side.

The easiest way to build it: place a row of 4 obsidian blocks on the ground for the bottom. Then place 3 more blocks vertically on each end (left and right sides). Finally, place 4 blocks across the top. The corners are shared — you do not double-count them. Step back and check that the inside space is empty and rectangular.

The frame does not have to be perfectly level, but it should be on relatively flat ground so you can step into it easily. You can build it indoors, outdoors, or underground — the location does not matter for the portal to work.

Lighting the Portal With Flint and Steel

Flint and steel is a tool that creates fire. You craft it by combining one flint (found by mining gravel) and one iron ingot (smelted from iron ore). Once you have flint and steel in your inventory, stand in front of the empty obsidian frame and right-click (or use your secondary action button) on any of the obsidian blocks. A purple swirling gateway will appear when ready inside the frame.

If nothing happens when you click, check that the frame is complete — sometimes a missing corner block is hard to spot. If the frame is correct and you still see no portal, try clicking a different obsidian block in the frame.

Once the portal is lit, it stays active. You do not need to light it again unless it gets destroyed (which happens if you break any of the obsidian blocks or if the block is destroyed by an explosion).

Stepping Through and What Happens Next

Walk into the purple gateway. Your screen will flash and you will be transported to the Nether — a dark, dangerous dimension filled with lava, hostile mobs, and valuable resources. You will appear near a Nether portal that corresponds to your Overworld portal. The Nether is much smaller in area than the Overworld, so traveling 8 blocks in the Nether equals roughly 64 blocks in the Overworld.

To return to the Overworld, find or build a Nether portal in the Nether and step through it. You will arrive back at your original Overworld portal (or very close to it). If your original portal was destroyed while you were in the Nether, you will spawn at the world spawn point instead, which can be far from where you started.

Always build your first portal near your base and keep it safe. If you plan to explore the Nether, consider building a second portal deeper in the Nether so you have a way back if your first portal is damaged.

Protecting Your Portal From Damage

Nether portals can be destroyed by breaking the obsidian blocks or by explosions from Ghasts (flying mobs in the Nether that shoot fireballs). Build your Nether portal in a protected location — inside a building, surrounded by non-flammable blocks, or in a spot where Ghasts cannot easily reach it.

If your portal is destroyed while you are in the Nether, you can build a new one using obsidian you brought with you, or you can search for a naturally generated Nether fortress and look for a portal there. Nether fortresses contain chests with useful items and are a landmark you can navigate back to.

Keep extra obsidian and flint and steel in a chest near your portal as backup. This way, if something goes wrong, you have the materials to repair or rebuild quickly.

Frequently Asked Questions

Can I build a Nether portal in Creative Mode?

Yes. In Creative Mode, you can place obsidian directly from your inventory without mining it. Light it with flint and steel the same way. Creative Mode is useful for testing portal placement or building without gathering materials.

What if I build a portal in the Nether — where do I end up in the Overworld?

The game calculates the location based on coordinates. A Nether portal at coordinates X, Z in the Nether corresponds to coordinates X×8, Z×8 in the Overworld. If you build a portal in the Nether at X=100, Z=100, stepping through takes you to the Overworld at X=800, Z=800. This is why Nether travel is useful for long-distance journeys.

Do I need to rebuild my portal every time I use it?

No. Once a portal is lit, it stays active until the obsidian blocks are broken or destroyed. You can use the same portal as many times as you want. The portal will not disappear on its own.

What blocks can I use instead of obsidian?

Only obsidian works for Nether portals. No other block will create a gateway. Crying obsidian (a lighter purple block found in the Nether) looks similar but does not work for portals.

Can I move a portal by breaking it and rebuilding it elsewhere?

Yes. Break the obsidian blocks, gather them, and build a new frame in a different location. Light the new frame with flint and steel. The old portal location will no longer work, and the new one will be your active portal.