The Basic Steps to Build a Nether Portal

A Nether portal in Minecraft is a rectangular frame made of obsidian blocks that transports you to the Nether dimension. You build it by placing obsidian in a 4×5 rectangle (the frame itself, not filled in), then lighting it on fire with flint and steel or a fire charge. The portal activates immediately and turns purple when you ignite it.

The minimum size is 4 blocks wide and 5 blocks tall on the inside of the frame. You can make it larger — up to 23×23 — but the smallest working portal uses 10 obsidian blocks total. The obsidian must form a complete rectangle with no gaps, or the portal will not activate.

Once lit, the portal creates a purple swirling surface you can walk through. Stepping into it transports you to the Nether. When you build a portal in the Nether and light it, you return to the Overworld (the normal world) at a corresponding location.

Key Takeaways

  • A Nether portal frame requires obsidian blocks arranged in a 4×5 rectangle, with the inside left empty.
  • You light the portal by right-clicking the obsidian frame with flint and steel or by throwing a fire charge at it.
  • Obsidian is found deep underground in the Overworld and can be mined only with a diamond or netherite pickaxe.
  • Portals in the Nether and Overworld are linked by coordinates — building a portal in one dimension creates a connection to the other.
  • You can move a portal by building a new one elsewhere; the old one remains but becomes inactive if you do not use it.

Finding and Mining Obsidian

Obsidian forms when water flows over lava source blocks. You will find it naturally in the Overworld near lava lakes, in the Nether, and in strongholds. The easiest way to get obsidian early in the game is to locate a lava lake, pour water over it, and mine the obsidian that forms.

You must use a diamond pickaxe or netherite pickaxe to mine obsidian. A stone, iron, or wooden pickaxe will not break it, and you will waste time. If you do not have a diamond pickaxe yet, you need to find diamonds first — they spawn below Y-level 16 in caves and ravines.

Mining obsidian is slow. Each block takes about 9.4 seconds with a diamond pickaxe. For a minimum 4×5 portal, you need 10 blocks, which takes roughly 90 seconds of mining time per block. Bring a pickaxe with the Efficiency enchantment to speed this up significantly.

Getting Flint and Steel to Light the Portal

Flint and steel is the tool you use to ignite the portal. You craft it by combining one flint and one iron ingot on a crafting table. Flint drops from gravel blocks when you mine them — usually one flint per 10 gravel blocks, though it is random. Iron ingots come from smelting iron ore in a furnace.

An alternative is a fire charge, which you craft from blaze powder, coal or charcoal, and gunpowder. Fire charges work the same way as flint and steel but are harder to obtain early in the game because they require blaze powder from the Nether — which you cannot reach without a portal.

Flint and steel is reusable and does not break after lighting a portal, so you only need to craft it once. Keep it in your inventory for future portal building.

Building Your First Portal Step by Step

Step 1: Gather 10 obsidian blocks and flint and steel. Find a flat location where you want the portal to stand.

Step 2: Place obsidian blocks in a rectangle shape. Start at one corner and build the frame: 4 blocks wide, 5 blocks tall. The inside should be completely empty — do not fill it in.

Step 3: Right-click on any obsidian block in the frame while holding flint and steel. A fire animation appears, and the portal ignites.

Step 4: The inside of the frame fills with purple swirling blocks. Walk into the purple area to enter the Nether. You will see a loading screen, then appear in the Nether.

Step 5: To return, build another portal in the Nether using the same method, or find the return portal that Minecraft creates automatically near your original location.

Understanding Portal Linking and Coordinates

Minecraft links portals between the Nether and Overworld using a coordinate system. When you build a portal in the Overworld at coordinates X=100, Z=100, Minecraft creates a corresponding portal in the Nether at X=12.5, Z=12.5 (the Nether is 8 times smaller). If you build a portal in the Nether, it links back to the Overworld at 8 times the coordinates.

This means if you build a portal in the Overworld and step through, you will exit near a specific location in the Nether. If you build a second portal in the Nether close to where you arrived, stepping through it takes you back to the Overworld near your original portal — but not exactly at it.

You do not need to understand the math to use portals. Just know that portals are connected by location, and building a new portal in either dimension creates a link to the other dimension at a corresponding spot.

Troubleshooting Portals That Will Not Light

If you right-click with flint and steel and nothing happens, check that the obsidian frame is complete with no gaps or missing blocks. Even one missing block prevents the portal from lighting. Count the blocks carefully: 4 wide, 5 tall, with the inside empty.

Make sure you are using flint and steel, not another item. If you crafted it correctly, it appears in your inventory as a small steel striker. If you are using a fire charge instead, throw it at the obsidian frame rather than right-clicking.

If the frame is complete and you have the right tool, try building the portal in a different location. Some players report that portals occasionally fail to light in certain spots, though this is rare. Rebuilding nearby usually solves it.

Moving or Deactivating a Portal

Once a portal is lit, it stays active until you break the obsidian frame. Breaking even one obsidian block deactivates the portal immediately. You can mine the obsidian with your diamond pickaxe and use it to build a new portal elsewhere.

If you build a new portal in a different location, the old portal remains as an empty frame but no longer functions. You can leave it standing or break it down for the obsidian. The new portal becomes your active connection to the Nether.

Portals do not despawn or disappear on their own. They remain until you or another player breaks them, so you can return to the same portal location many times.

Frequently Asked Questions

Can I make a portal smaller than 4×5?

No. The minimum working size is 4 blocks wide and 5 blocks tall on the inside. Smaller frames will not light. You can make portals larger, but smaller does not work.

What happens if I break obsidian blocks while standing in the portal?

You will be pushed out of the portal and take damage. Breaking the frame deactivates the portal immediately, so you cannot use it to travel. Rebuild the frame if you want to use it again.

Do I need a specific tool to light the portal?

You need either flint and steel (right-click the frame) or a fire charge (throw it at the frame). No other tool or item will light it. Flint and steel is easier to obtain early in the game.

Can I build a portal underwater or in the rain?

No. Water extinguishes the portal immediately after you light it. Build your portal in a dry location, indoors or under a roof. Rain does not extinguish it, but standing water will.

What if my portal takes me to a different location than I expected?

Portals link by coordinates, so the Nether portal may not be directly below or above your Overworld portal. This is normal. Build a new portal in the Nether near where you arrived, and it will take you back to the Overworld close to your original location.