You’re standing there with a diamond pickaxe and a dream, staring at a wall of obsidian. Or maybe you don't even have the diamonds yet and you're trying to figure out that weird lava-casting trick you saw on a speedrun. Honestly, learning how to build the nether portal is basically the "graduation ceremony" of Minecraft. It’s the moment you stop worrying about skeleton archers in the woods and start worrying about literal ghosts shooting fireballs at your face.
It sounds simple. Get purple rocks, make a rectangle, light it on fire. Done. But if you’ve ever ended up in a basalt delta surrounded by magma cubes with no way home, you know there’s more to it than just the layout.
The Basic Math of Obsidian
A standard portal is a 4x5 vertical rectangle. That's the classic look. You need ten blocks of obsidian minimum if you skip the corners, or fourteen if you want it to look "fancy." Obsidian is famously stubborn. You can’t just mine it with iron; you need diamonds. Specifically, a diamond pickaxe (or netherite, if you’re already fancy).
Most people just dig a hole, pour water on a lava pool, and start clicking. It takes forever. Each block takes about 9.4 seconds to break with a diamond tool. That’s a lot of standing around.
If you're going for the 10-block "budget" version, you place two on the bottom, three on each side, and two on top. You can put dirt, cobblestone, or nothing at all in the four corners. It doesn't change how the portal works. It just saves you the headache of mining four extra blocks of the hardest material in the Overworld.
Speedrunning the Portal: The Bucket Method
Maybe you don't have diamonds. Maybe you're lazy. I get it. This is where "casting" comes in. You basically use a bucket of water and a nearby lava pool to mold the obsidian exactly where it needs to be.
First, find a flat-ish area near lava. Build a small "L" shape out of dirt. Pour your water against it. Now, you take your lava buckets and right-click the water. Boom. Instant obsidian. You build the frame one block at a time by moving the water around. It’s tricky because if you mess up, you’ve just placed a permanent block of obsidian where your front door should be.
Expert tip: Use a "mold." If you place a pillar of three blocks and put water at the top, the water flows down the sides. You can then place lava into the flowing water to create the vertical pillars of the portal frame without having to climb up and down constantly.
Lighting the Fuse
Once the frame is standing, you need a spark. A Flint and Steel is the standard choice—one iron ingot and one piece of flint. If you're stuck and don't have iron, you've got options. Fire charges work. You can even bait a Ghast into shooting the portal frame if you're feeling suicidal, or use wood and lava to start a fire nearby and hope the "fire spread" hits the inside of the frame.
🔗 Read more: The Clix Icon Skin: Why It’s Actually a Big Deal for Fortnite
The portal lights up with a purple, swirling haze. That’s your cue.
What No One Tells You About Portal Linking
This is where things get messy. One block in the Nether equals eight blocks in the Overworld. This is a hard rule. If you build two portals in your base that are too close together, they’ll both probably spit you out at the same location in the Nether.
If you want to travel long distances, you have to do the math. Take your Overworld coordinates ($X$ and $Z$). Divide them by 8. Go into the Nether and build your second portal at those exact coordinates. If you don't, the game gets confused and links you to the "nearest" existing portal, which might be 500 blocks away from where you actually want to be.
Common Mistakes That Ruin Your Run
- Floating Portals: Sometimes the game spawns your Nether-side portal over a giant lake of lava. Always bring a few stacks of cobblestone with you. Cobblestone is blast-resistant to Ghast fireballs; netherrack is not.
- The "Trapped" Portal: If a Ghast shoots your portal, the purple part disappears. You are now stuck in hell. Always carry a spare Flint and Steel. If you forgot one, you’ll have to hunt down a Fortress to find iron in a chest or kill a Wither Skeleton and a Blaze to craft a Fire Charge.
- Corner Cutting: While the 10-block portal works, it's easier for mobs to accidentally wander through. Consider building a fence or a small room around your portal. Nothing ruins a Minecraft morning like a Creeper coming through the portal while you're sorting your chests.
Dimensions Beyond the 4x5
You aren't stuck with that tiny rectangle. A portal can be as large as 23x23. Why would you do this? Mostly for style, or if you're building a massive gold farm. Massive portals allow more "ticks" for pigmen to spawn, which is the backbone of high-level industrial Minecraft builds.
You can also make them horizontal? No, wait. That’s an End Portal. Nether portals must be vertical. If you try to build a flat one on the ground, you’re just making a very expensive purple swimming pool that doesn't work.
Survival Steps After Stepping Through
The second you load into the Nether, crouch. Seriously. The game sometimes spawns you on a single ledge of glowing stone. One step forward and you're swimming in lava, losing your enchanted gear forever.
- Encase the portal immediately. Use cobblestone. It’s ugly, but it’s fireproof and Ghast-proof.
- Write down your coordinates. Seriously. Use F3 or a piece of paper. If you get lost, you need to know where home is.
- Gold armor. Wear at least one piece. Boots, a helmet, whatever. Piglins are aggressive unless they think you're one of them because of your shiny outfit.
- Bring wood. There are "trees" in the Nether now (Crimson and Warped forests), but having a stack of regular oak planks can save your life if you need to make a crafting table in a pinch.
Building the portal is just the beginning. The Nether is a punishing place, but it’s the only way to get Potion Ingredients, Ancient Debris for Netherite armor, and the Blaze Rods you need to actually "beat" the game. Get your obsidian, check your coordinates, and don't forget your flint and steel. You're going to need it.
Next Steps for Your Minecraft Journey:
- Verify your coordinates: Press F3 in the Overworld, divide your $X$ and $Z$ positions by 8, and mark that spot for your Nether-side hub.
- Gather safety supplies: Craft a full stack of cobblestone slabs and a spare flint and steel before you cross the threshold.
- Equip gold: Swap your diamond or iron boots for gold boots to ensure Piglins remain neutral during your initial exploration.
- Secure the entrance: Once through, immediately build a 3x3x3 cobblestone room around the portal to protect it from Ghast projectiles.