The Basic Steps to Build Your Portal

A Nether portal is a rectangular frame made of obsidian blocks that you light on fire to travel to the Nether dimension. You need at least 10 obsidian blocks to build the smallest working portal, which is a 4-block-wide by 5-block-tall frame (the corners are optional). Place the obsidian in a rectangle shape, then use flint and steel or a fire charge to ignite the purple fire inside the frame.

The portal doesn't need to be perfectly symmetrical or have corners filled in — only the frame matters. Once you light it, the purple swirling texture will appear inside, and you can walk through to enter the Nether. The portal will stay active until you break the obsidian blocks or the fire goes out.

Key Takeaways

  • You need obsidian blocks and either flint and steel or a fire charge to create a working portal.
  • The minimum frame is 4 blocks wide and 5 blocks tall, using 10 obsidian blocks total.
  • You can find obsidian by mining it with a diamond or netherite pickaxe where lava meets water, or by collecting it from the Nether itself.
  • Once lit, the portal creates a two-way passage — you can return to the Overworld by building or finding another portal in the Nether.

Where to Find or Make Obsidian

Obsidian forms naturally when flowing lava touches water. The easiest way to collect it is to find a lava lake near water, pour water over the lava, and mine the obsidian blocks that form. You need a diamond pickaxe, netherite pickaxe, or better to break obsidian — stone and iron pickaxes will not work.

If you do not have a diamond pickaxe yet, you can find obsidian in the Nether itself, in ruined portals and fortress structures. You can also craft obsidian by pouring water over a lava source block, though this is slower than mining it from naturally formed deposits. Some players create a simple obsidian farm by repeatedly pouring lava and water to generate blocks they can harvest.

Getting Flint and Steel to Light the Portal

Flint and steel is the most common tool for lighting a portal. You craft it by combining one iron ingot and one flint in a crafting table. Flint drops from gravel blocks when you mine them — usually one flint per three gravel blocks. Iron ingots come from smelting iron ore in a furnace.

If you do not have flint and steel ready, a fire charge also works. Fire charges are crafted from blaze powder, coal or charcoal, and gunpowder. They are less common early in the game but are useful if you are already in the Nether and need to light a portal to return home. You can also use a flaming arrow or lava bucket in a pinch, though these are less reliable.

Building the Frame in the Right Location

Choose a location where you have space to build a 4-by-5 frame without obstacles. The portal does not need to be on the ground — you can build it on a platform, inside a structure, or even suspended in the air. Make sure the area inside the frame is clear so you can walk through without hitting blocks.

It is a good idea to build your first portal near your base or spawn point, so you know where to return to. Mark the location with torches or a sign so you can find it again. If you build a portal far from home, write down the coordinates or place a beacon nearby so you do not get lost when you come back from the Nether.

What Happens When You Enter the Nether

When you step through the portal, you will arrive in the Nether dimension. The Nether is a dangerous place with lava lakes, hostile mobs like ghasts and blazes, and blocks that burn if you are not careful. Bring armor, weapons, and food before entering, especially on your first trip.

Portals in the Nether work on a coordinate system — if you build a portal at coordinates X: 100, Z: 100 in the Overworld, a portal in the Nether at X: 12.5, Z: 12.5 will link back to it (the Nether is 8 times smaller in scale). This means you can travel long distances in the Overworld by going through the Nether and coming back out, though this is risky without proper preparation.

Fixing a Broken or Lost Portal

If your portal breaks because obsidian blocks were destroyed, you can rebuild it by placing new obsidian blocks in the frame and lighting it again. If you lose track of where your portal is in the Nether, you can build a new one there and light it — it will create a new link back to the Overworld, though not necessarily to your original portal.

If you are stuck in the Nether without a way to light a portal, your only option is to find a ruined portal (which spawn naturally in the Nether) and repair it, or gather the materials to build and light a new one. This is why it is important to carry flint and steel or a fire charge whenever you enter the Nether.

Frequently Asked Questions

Can I build a Nether portal without obsidian?

No, obsidian is the only block that works for a portal frame. You cannot use other blocks or materials as a substitute. However, you can find obsidian relatively quickly by locating lava and water and combining them.

What is the biggest portal I can build?

The largest portal frame is 23 blocks wide by 23 blocks tall. Larger frames will not work. Most players build the minimum 4-by-5 size to save obsidian, but bigger portals look more impressive and do not cost much more.

Do I need to light every block in the frame?

No, you only need to light one block of the interior. The fire will spread to fill the entire frame automatically. Use flint and steel or a fire charge on any empty space inside the obsidian rectangle.

Can mobs come through my portal from the Nether?

Yes, hostile mobs can walk through portals just like you can. Build your portal in a safe location or create a barrier around it so mobs cannot reach your base when they come through.

What happens if I break the obsidian while standing in the portal?

You will be pushed out of the portal and back into the dimension you were in. Breaking obsidian blocks does not trap you — you can always rebuild the frame and light it again.