How to Make a Nether Portal in Minecraft

If you want to step from the Overworld into the Nether, you need a portal — and you need to build it yourself. The good news is the recipe is simple: a rectangular obsidian frame, plus a way to set it on fire. The trickier part is actually getting the obsidian, and (later on) making sure two portals link up the way you expect them to.

This guide walks through everything: the minimum frame size, how to get obsidian without a diamond pickaxe, lighting the portal, and the 8:1 ratio that decides where you come out on the other side. All steps work in current Java and Bedrock editions.

What You Need

To build a working Nether portal you need:

• At least 10 blocks of obsidian for the smallest legal frame.
• Something to light it. Flint and steel is the standard choice.
• A safe spot to build it (not right next to a creeper).

That's it. You don't need a Nether reactor, a special block, or any redstone. The portal is just the frame plus the fire.

How Big Does the Frame Have To Be?

A Nether portal is a vertical rectangle of obsidian with a minimum size of 4 wide by 5 tall and a maximum of 23×23, according to the Minecraft Wiki. The four corners of the frame are optional — the portal still ignites without them — which is why the bare minimum is 10 obsidian instead of 14.

If you want the cleanest look, build the full 4×5 with corners (14 obsidian). If you're in a rush or running short on obsidian, skip the corners:

. X X .
					X . . X
					X . . X
					X . . X
					. X X .
					

That layout uses 10 obsidian and lights up the same way.

You can also build it bigger. Larger portals look impressive and let multiple players or mobs through at once, but they don't function any differently from the minimum size.

Getting Obsidian (Two Routes)

Obsidian is created when a water source touches a lava source. To mine an obsidian block as an item you need a diamond or netherite pickaxe — anything weaker just destroys it without dropping anything.

Route 1: Mine It With a Diamond Pickaxe

If you've already got diamonds, find a lava pool, pour a bucket of water over it from a safe spot, and mine the obsidian that forms. Each block takes about 9.4 seconds to break with a diamond pickaxe — bring food and a few extra picks if you're harvesting a lot.

Route 2: Cast It In Place (No Diamond Pickaxe Needed)

If you don't have diamonds yet, you can build the portal frame in place using only buckets. Place lava source blocks where you want the obsidian to be, then drop water on top so each lava source converts to obsidian. The Minecraft Wiki tutorial on obsidian farming covers a few patterns for doing this safely.

The catch: blocks made this way can't be picked back up unless you eventually mine them with a diamond or netherite pickaxe. If you make a mistake, you'll have to work around it. Plan the frame with a chest, a sketch, or just a reference image on a second screen before you start pouring lava.

Step-by-Step: Building the Portal

1. Mark Out the Frame

Pick a flat spot. The portal is vertical, so you need at least 5 blocks of clearance above the floor. Place a single obsidian block, then count two blocks across — the gap between the two side pillars should be 2 wide (the inside of the portal will be 2 wide and 3 tall).

2. Place the Obsidian

Build the bottom row (2 blocks if you skip corners, 4 if you keep them), then the two vertical pillars, then the top row. Don't worry about the corners — they're decorative.

3. Light It

Craft flint and steel from 1 iron ingot + 1 flint in any 2x2 grid (you don't need a crafting table), per the Minecraft Wiki. Right-click any inside face of the frame to set it on fire. The frame fills with a purple swirl — that's the portal.

If you don't have flint and steel, anything that creates fire inside the frame works: a fire charge, a Ghast fireball, a lightning strike, or fire spreading from a flammable block next to the portal. Flint and steel is just the easiest.

Why Your Portal Came Out in the Wrong Place

This is the part players get wrong all the time. The Nether is smaller than the Overworld: every 1 block you walk in the Nether is equivalent to 8 blocks in the Overworld.

When you step into a portal, the game does this:

You're going	What happens to your X/Z coordinates	Y
Overworld → Nether	Divided by 8	Stays the same
Nether → Overworld	Multiplied by 8	Stays the same

The game then looks for an existing portal near that target spot. If it finds one within range, you come out of that portal. If it doesn't, it builds a new one for you — and that "new portal" is often jammed into a wall, dropped into lava, or stuck on the ceiling of a cave.

Linking Two Portals Reliably

If you want a specific Overworld portal to connect to a specific Nether portal, you have to build both manually at matching coordinates.

1. Note Your Overworld Portal Coordinates

Press F3 (Java) or turn on coordinates in world settings (Bedrock). Write down X, Y, Z.

2. Calculate the Nether Coordinates

Divide X and Z by 8. Y stays the same. Example:

• Overworld portal at (240, 70, -800)
• Target Nether coordinates: (30, 70, -100)

A handy Nether portal calculator does the math for you, but it's quick enough to do in your head.

3. Travel to the Nether and Build the Second Frame

Walk to the calculated Nether coordinates and place a fresh obsidian frame there. Light it. Now both portals exist exactly where the game expects them, and they'll link to each other instead of generating new ones.

4. Spacing Tips

If you plan to build several portals (a Nether highway, for example), keep your Overworld portals at least 1,024 blocks apart. That's 128 Nether blocks — far enough that their search ranges won't overlap and steal each other's links. Closer than that, and stepping through one portal might pop you out of the wrong one.

Common Mistakes

• Frame is too small. 3×4 won't ignite. The minimum is 4 wide by 5 tall counted from the outside corners.
• You used cobblestone or basalt for the frame. It has to be obsidian. Crying obsidian doesn't work either — it's only used for respawn anchors.
• You're trying to light the obsidian itself. Aim flint and steel at the inside of the frame, not at the obsidian blocks.
• Built two portals close together and they keep linking to the same spot. Move them at least 1,024 Overworld blocks apart and rebuild.
• Portal spawned you over lava in the Nether. Break the new portal, calculate proper coordinates, and rebuild manually at a safer spot.

Quick Recap

A Nether portal is 10–140 obsidian arranged as a 4×5-to-23×23 vertical frame, ignited from the inside with flint and steel or another fire source. Where you come out is decided by your X/Z divided by 8 (Y unchanged), and if you want predictable links, build the matching portal yourself at the calculated coordinates.

Once you're through, the Nether opens up the rest of the game — blaze rods, ancient debris, fortresses, and the route to the End. The portal is the cheapest 10 blocks of progression you'll build all playthrough.