How to Build a Nether Portal in Minecraft

The Nether Portal is one of Minecraft's most iconic structures — a glowing obsidian gateway that transports you to the Nether dimension, a dangerous underworld filled with rare resources, hostile mobs, and unique biomes. Building one correctly is a milestone moment in any survival playthrough, but the process involves a few important details that trip up new players.

Here's everything you need to know about constructing a Nether Portal, from materials to activation.

What You Need to Build a Nether Portal

Before you start building, you'll need two core things:

• Obsidian — the primary building material
• A fire source — to activate the portal

Obsidian

Obsidian is created wherever flowing water meets a lava source block. It's one of the hardest blocks in the game and can only be mined with a diamond pickaxe or higher (netherite also works). Each block takes roughly 10 seconds to mine, so prepare accordingly.

You'll need a minimum of 10 obsidian blocks for the smallest valid portal frame, though a full rectangular frame uses 14. The difference matters — more on that below.

Fire Source

To activate the portal, you need to ignite the inside of the frame. The most reliable method is a flint and steel, crafted from one iron ingot and one flint (dropped from gravel). Alternatively, a fire charge works if you happen to have one.

The Standard Portal Frame Dimensions

A Nether Portal frame must form a hollow rectangle made entirely of obsidian. The minimum size is:

The minimum viable portal uses 10 obsidian blocks — two columns of three on the sides, and two blocks across the top and bottom, with the corners left open. Corner blocks are optional; the portal works without them, saving you 4 obsidian.

Larger portals (up to 23×23) are valid and create a bigger glowing opening, but they still connect to the Nether the same way as a minimum-size portal.

Step-by-Step: Building the Portal 🔥

1. Choose your location Place your portal somewhere flat and accessible. Many players build near their base or home spawn point for easy access.

2. Lay the base Place 2 obsidian blocks side by side on the ground. These form the bottom of the frame.

3. Build the sides Stack 3 obsidian blocks vertically on each end of the base. You should now have two columns rising from either end of your base row.

4. Cap the top Place 2 obsidian blocks horizontally across the top, connecting the two columns. Your frame should now be a hollow rectangle — 4 wide and 5 tall.

5. Activate the portal Stand inside the frame and use your flint and steel on the bottom interior block (or any interior block). The inside will fill with a swirling purple/violet light — that's the active portal.

If nothing happens, check that your frame is fully closed with no gaps, and that all blocks are obsidian (not crying obsidian, which looks similar but cannot form portals).

Common Mistakes and How to Avoid Them

Using crying obsidian by mistake Crying obsidian is a different block — it has a dripping purple particle effect and is used to craft a respawn anchor. It looks similar but is completely non-functional as a portal frame material.

Gaps in the frame Any missing block breaks the structure. The game requires a perfectly sealed rectangular border of obsidian. Double-check every corner and side.

Wrong pickaxe Obsidian cannot be mined with anything below diamond tier. Using a gold, iron, or stone pickaxe will just destroy the block without dropping it. Always have a diamond (or netherite) pickaxe ready before harvesting.

Forgetting the fire source The portal doesn't activate on its own. You must manually ignite it. Craft flint and steel before heading out to build.

Alternative: The Bucket Method

If you don't want to mine obsidian the traditional way, you can create it in place using lava buckets and water. By carefully placing lava source blocks in the exact shape of your portal frame and then running water over them, you can form the obsidian structure without ever mining a single block. This technique takes more planning and a reliable lava source (typically a lava lake underground), but it's useful early in survival when diamond tools aren't available yet.

What Happens When You Step Through

Entering the active portal triggers a 4-second transition — your screen fills with a swirling purple effect — and you emerge in the Nether. The game automatically generates a corresponding portal on the Nether side, typically linked to your entry point through the 8:1 coordinate ratio (one block traveled in the Nether equals eight blocks in the Overworld).

This ratio matters for players building Nether highways or travel networks, since portal placement relative to Nether coordinates directly affects where you exit in the Overworld.

Variables That Affect Your Experience

How straightforward building a Nether Portal feels depends heavily on a few factors specific to your playthrough:

• Which edition you're playing — Java and Bedrock both support portals, but some visual and sound details differ slightly
• How far into survival you are — early-game players will need to work harder to source obsidian safely
• Whether you're playing on a server — multiplayer servers may have plugins or rules affecting portal linking behavior
• Your world seed — some seeds generate lava lakes and obsidian sources much closer to spawn than others

The mechanics are the same across setups, but how long it takes to gather materials and where your portals end up in the world depends entirely on the conditions of your specific game.