A Nether Portal Needs 14 Obsidian Blocks Arranged in a Specific Frame

A Nether Portal is a rectangular frame made of obsidian that opens a doorway to the Nether dimension. The frame must be at least 4 blocks wide and 5 blocks tall on the inside — that means you need 14 obsidian blocks total, arranged in a hollow rectangle. You do not fill in the middle; the empty space is where the purple portal appears once you light it.

The exact shape is: 4 blocks across the bottom, 4 blocks across the top, and 3 blocks on each side (the corners are shared). Once the frame is built, you light it by clicking the inside of the frame with flint and steel, and the purple swirling texture fills the empty space.

Key Takeaways

  • Obsidian is the only block that works for a Nether Portal frame, and you must mine it with a diamond or netherite pickaxe.
  • The minimum frame size is 4 blocks wide and 5 blocks tall (14 obsidian blocks total), but you can build it larger if you want.
  • You light the portal with flint and steel by clicking inside the frame; the portal activates immediately once lit.
  • Obsidian is found deep underground near lava, or you can create it by pouring water onto lava source blocks.

Finding or Creating Obsidian

Obsidian does not spawn naturally in large quantities, so you will need to either mine it or create it. To mine obsidian, you must use a diamond pickaxe or better (netherite pickaxe). A stone, iron, or wooden pickaxe will not work — the block will break but you will not collect it.

Obsidian forms naturally where lava meets water. You can find it near lava lakes deep underground, usually below Y-level 0 (you can check your Y-coordinate in the debug screen by pressing F3 on Java Edition). The faster method is to create obsidian yourself: find a lava source block, pour water onto it from above or the side, and the lava turns into obsidian instantly. You can repeat this as many times as you need by finding more lava sources.

If you are in Creative mode, you can simply grab obsidian from the inventory. Survival mode requires the mining or crafting approach.

Building the Frame Step by Step

Choose a flat area where you want the portal to stand. Obsidian is heavy and permanent, so pick a location you actually want to use as an entrance to the Nether.

Place your obsidian blocks in this pattern: lay 4 blocks in a line for the bottom, then stack 3 blocks up on each end, then cap it with 4 blocks across the top. The result is a hollow rectangle. The inside space should be 4 blocks wide and 5 blocks tall. You can build the frame on the ground, on a platform, or even floating in the air — the portal works anywhere.

Double-check that the frame is complete and the middle is empty. If you accidentally filled in the middle, you will need to break out the obsidian blocks and rebuild.

Lighting the Portal with Flint and Steel

Once the frame is built, you need flint and steel to activate it. Flint and steel is crafted from one flint and one iron ingot. Flint drops from gravel when you mine it (not every gravel block drops flint, but roughly one in three does). Iron ingots come from smelting iron ore in a furnace.

Hold the flint and steel in your hand and right-click (or use your secondary action button) on any block inside the portal frame. A purple, swirling texture fills the empty space, and the portal is now active. You can walk through it to enter the Nether.

If the portal does not light, check that the frame is complete with no gaps, and that you clicked inside the frame rather than on the obsidian blocks themselves.

Portal Size and Customization

The minimum frame is 4 wide by 5 tall, but you can build larger portals if you want. A 5-by-6 frame, a 6-by-7 frame, or even bigger all work fine. Larger portals do not function differently — they just look more impressive and take more obsidian.

The frame must be rectangular. You cannot build a circular portal, a T-shaped portal, or any other shape. The game only recognizes the standard rectangular frame.

You can decorate around the portal with other blocks, but the obsidian frame itself must remain clear and unobstructed for the portal to work.

What Happens When You Enter the Nether

When you walk through an active portal, you are transported to the Nether dimension. The Nether is a dangerous place filled with lava, hostile mobs, and hazardous terrain. You will spawn near the coordinates where your portal is, but the Nether uses a different coordinate system — 1 block in the Nether equals 8 blocks in the Overworld.

To return to the Overworld, you can either build another portal in the Nether and light it, or find the original portal you came through and walk back through it. Portals are two-way doors.

Troubleshooting Portal Problems

If your portal will not light, the most common cause is an incomplete frame. Check all four sides and both the top and bottom to make sure no obsidian blocks are missing. Even a single gap will prevent the portal from activating.

If you are clicking but nothing happens, make sure you are holding flint and steel and clicking inside the frame, not on the obsidian blocks. Also confirm you have the right tool — a regular steel ingot or flint alone will not work.

If the portal lights but you cannot walk through it, try jumping or moving at a different angle. Sometimes the collision detection is finicky, and approaching from a different direction helps.

Frequently Asked Questions

Can I build a Nether Portal in the Nether itself?

Yes. You can gather obsidian in the Nether (it spawns naturally there) and build a portal to return to the Overworld or travel to a different location in the Nether. The mechanics are identical.

What if I lose my portal in the Nether?

Build a new one using obsidian you find or create in the Nether. Write down your coordinates before you leave the Overworld so you know roughly where to look. If you are completely lost, your best option is to find lava, create obsidian, and build a new portal to get home.

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

No. Once a portal is built and lit, it stays active permanently. You can walk through it as many times as you want without rebuilding it.

Can I move a portal or break it down and rebuild it elsewhere?

Yes. Obsidian can be mined with a diamond or netherite pickaxe and moved to a new location. You can disassemble a portal and rebuild it somewhere else, then light it again with flint and steel.

What is the fastest way to get 14 obsidian blocks?

Find a lava lake underground, pour water on it to create obsidian, and mine it with a diamond pickaxe. This is faster than searching for naturally occurring obsidian. You can create as much obsidian as you need this way.