A nether portal is your doorway to the Nether, the fiery dimension with blaze rods, netherite, fortresses, and fast overworld travel. Building one comes down to two things: an obsidian frame and a way to light it. This guide covers the exact size, how to get obsidian without a diamond pickaxe, lighting the portal, and linking two portals together.
Everything here is confirmed in the current 2026 version of Minecraft (26.2).
Quick answer: build a vertical obsidian frame at least 4 wide and 5 tall (the four corners are optional, so 10 obsidian is the minimum), then light the inside with flint and steel.
Nether Portal at a Glance
| Detail | Value |
|---|---|
| Frame | Obsidian, 4×5 minimum (up to 23×23) |
| Obsidian needed | 10 (corners optional) or 14 with corners |
| Light it with | Flint and steel or a fire charge |
| Interior | 2 wide x 3 tall opening |
Step 1: Get Obsidian
Obsidian forms when water touches a lava source block. You have three ways to get it for the frame:
- Mine it where lava has already cooled, but this needs a diamond or netherite pickaxe (any lesser tool destroys it).
- Cast it in place (no diamond pickaxe needed): place lava source blocks in the shape you want using a temporary block like dirt to hold them, then pour water over each to turn it into obsidian, and clear away the temporary blocks. Our obsidian guide walks through this.
- Complete a ruined portal you find in the world, filling in its missing obsidian.
You need at least 10 blocks for a minimum portal.
Step 2: Build the Frame
Build a standing rectangle that is 4 blocks wide and 5 blocks tall on the outside, leaving a 2×3 hole in the middle. You do not need to place the four corner blocks, which is why 10 obsidian is enough. You can go bigger (up to 23×23) if you want a grand entrance, but the minimum works exactly the same.
Step 3: Light It
Take flint and steel (1 flint + 1 iron ingot) and use it on the inside face of the frame. The opening fills with a swirling purple portal. A fire charge, a ghast fireball, lightning, or fire spreading into the frame will also light it, but flint and steel is the standard. Step into the purple and you are off to the Nether.
Linking Two Portals
Here is the trick that makes portals powerful for travel: 1 block in the Nether equals 8 blocks in the Overworld. So the Nether is a shortcut: walk a short distance there, and you cover eight times the ground back home.
To make two specific portals connect reliably, note your Overworld portal’s coordinates (F3 on Java, or turn on coordinates on Bedrock), divide the X and Z by 8, and build your Nether portal at those coordinates. The height does not matter for linking, only X and Z. Do the reverse (multiply by 8) if you start in the Nether. Building portals at matching coordinates stops them from linking to the wrong destination.
Frequently Asked Questions
Build a vertical obsidian frame at least 4 wide and 5 tall (10 obsidian, corners optional), then light the inside with flint and steel. The opening becomes a purple portal to the Nether.
Ten blocks for the minimum 4×5 frame if you skip the corners, or fourteen if you include them. Larger portals up to 23×23 are optional.
Yes. Instead of mining obsidian, cast it in place: put lava where you want each block (held by a temporary block) and pour water on it to make obsidian. You can also complete a ruined portal.
Flint and steel is the usual way, used on the inside of the frame. A fire charge, a ghast fireball, or lightning also works.
One Nether block equals eight Overworld blocks. Divide your Overworld portal’s X and Z coordinates by 8 and build the Nether portal there (multiply by 8 going the other way). Height does not affect linking.
No. The four corner blocks are optional, which is why the minimum is 10 obsidian. The game adds corners to naturally generated portals, but you can leave them off.
A nether portal is one of the biggest milestones in Minecraft: gather ten obsidian (or cast it with lava and water), stand up a 4×5 frame, and strike it with flint and steel. Learn the 8-to-1 coordinate trick and your portals become the fastest travel network in the game.
