What You Need to Build a Nether Portal

A Nether portal requires 14 blocks of obsidian arranged in a rectangular frame. The frame must be at least 4 blocks wide and 5 blocks tall on the inside, though the standard size is 4×5. You do not need to fill the interior — only the frame itself activates the portal.

Obsidian is the only block that works. You obtain it by pouring water onto lava source blocks (not flowing lava). When water touches a lava source, it converts to obsidian instantly. The easiest method is to find a lava pool, pour water into it from a bucket, and mine the resulting obsidian with a diamond or netherite pickaxe. A wooden, stone, or iron pickaxe will not break obsidian fast enough.

You need a flint and steel to light the portal once the frame is built. Flint and steel is crafted from one flint (found by mining gravel) and one iron ingot (smelted from iron ore). Strike the frame with flint and steel, and the purple portal activates.

Key Takeaways

  • Obsidian is obtained by pouring water onto lava source blocks, and you need a diamond or netherite pickaxe to mine it.
  • The frame must be at least 4 blocks wide and 5 blocks tall on the inside, with only the border built — the center stays empty.
  • Flint and steel is crafted from flint (mined from gravel) and an iron ingot, and is used to activate the completed frame.
  • The portal activates instantly once you strike the frame with flint and steel, and stepping through takes you to the Nether.

Finding and Mining Obsidian

Lava pools are common in the Overworld, especially near water. Look for areas where lava and water are close together, or create your own obsidian by bringing water to a lava pool. Hold a water bucket and right-click (or use your secondary action button) to pour water directly onto a lava source block. The lava converts to obsidian immediately.

Once obsidian forms, equip your diamond or netherite pickaxe and mine it. Obsidian takes about 9.4 seconds to break with a diamond pickaxe and 7.5 seconds with netherite. You need 14 blocks total for a standard portal, though you can mine extra in case you make mistakes building the frame.

If you cannot find lava near the surface, dig down to Y-level 0 or lower, where lava pools are more frequent. Bring a water bucket and a pickaxe, and you can create obsidian anywhere underground.

Crafting Flint and Steel

Flint drops from gravel when you mine it with a shovel. Gravel is found on beaches, in riverbeds, and underground. Mine several blocks of gravel to collect flint — you need only one, but extras are useful for other crafting recipes.

Iron ore is smelted into iron ingots in a furnace. Mine iron ore (found underground at any depth) and place it in a furnace with fuel like wood or coal. One iron ore produces one iron ingot after smelting. Open your crafting menu, place one flint and one iron ingot diagonally in the crafting grid, and you get flint and steel.

Building the Frame

Place your obsidian blocks in a rectangular outline. The standard size is 4 blocks wide and 5 blocks tall on the inside, which means the outer frame is 6 blocks wide and 7 blocks tall. You can build it larger — the maximum is 23×23 on the inside — but the minimum is 4×5.

The frame does not need a top or bottom. You only need the four vertical sides. Place obsidian blocks in a rectangle on the ground, then stack them upward until you reach the desired height. The corners must connect, and there cannot be gaps in the frame.

Once the frame is complete, stand in front of it and hold flint and steel. Right-click (or use your secondary action button) on any obsidian block in the frame. The interior fills with purple swirling texture, and the portal is active. You can now step through to enter the Nether.

What Happens When You Enter

Stepping into an active Nether portal takes you to the Nether dimension. You appear near a corresponding portal in the Nether, which forms automatically if one does not already exist. The Nether is a dangerous dimension filled with lava, hostile mobs, and hazardous terrain.

To return to the Overworld, find or build another Nether portal in the Nether and step through it. You will return to the Overworld near your original portal. Portals remain active indefinitely unless you break the obsidian frame.

Repairing or Destroying a Portal

If obsidian blocks in your frame break, the portal deactivates. You can repair it by replacing the missing obsidian blocks. If you want to destroy a portal, mine the obsidian blocks with a diamond or netherite pickaxe. The portal closes immediately when the frame is broken.

Portals can be destroyed by ghasts (flying mobs in the Nether that shoot fireballs) or by other players in multiplayer. If your portal is destroyed while you are in the Nether, you can build a new one using obsidian you have mined there, or you can find the original portal location and rebuild it.

Common Mistakes to Avoid

Do not use flowing lava to make obsidian — only lava source blocks convert to obsidian when water touches them. Flowing lava becomes cobblestone instead. Identify a lava source by looking for a lava block that does not flow in any direction, or pour water on the lava and check what forms.

Do not forget to light the portal with flint and steel. A completed frame that is not lit does nothing. If you build the frame and nothing happens, you are missing the flint and steel activation step.

Do not build the portal in a dangerous location. Portals can be destroyed by explosions or hostile mobs. Build your portal in a safe, enclosed area or at least away from lava and cliffs.

Frequently Asked Questions

Can I build a Nether portal with other blocks?

No. Only obsidian works for the frame. No other block, even decorative blocks that look similar, will activate a portal.

What if I do not have a diamond pickaxe yet?

You cannot mine obsidian without a diamond or netherite pickaxe. If you do not have one, mine diamonds first (found deep underground, usually below Y-level 16) and craft a diamond pickaxe. Alternatively, find obsidian in the Nether and bring it back to the Overworld.

Do I need to build the portal frame in a specific direction?

No. The frame works facing any direction. Build it wherever is convenient for your base or travel route.

Can I make a smaller or larger portal?

Yes. The minimum is 4 blocks wide and 5 blocks tall on the inside. You can build larger portals up to 23×23 on the inside. Larger portals use more obsidian but function the same way.

What happens if I break the portal while I am inside it?

You stay in the Nether. You will need to build a new portal using obsidian you find there, or locate and rebuild your original portal in the Overworld to return home.