How to Build a Nether Portal in Minecraft With or Without a Diamond Pickaxe

Building a Nether portal is the most significant milestone in a Minecraft survival world. It serves as the gateway to the Nether—a dangerous, fire-filled dimension essential for obtaining Blaze Rods, Nether Wart, Soul Sand, and the materials needed for Netherite gear. While the concept seems simple—a rectangular frame of obsidian lit with fire—there are several methods to achieve this depending on your current resources and progression level.

To build a standard Nether portal, you need at least 10 blocks of obsidian arranged in a 4x5 vertical rectangle and a tool to ignite the interior, such as flint and steel.

Essential Materials for a Nether Portal

Before starting construction, you must gather specific materials. The difficulty of this step depends entirely on whether you have a Diamond Pickaxe or intend to use more advanced "casting" techniques.

1. Obsidian Blocks

Obsidian is formed when water flows over a stationary lava source block. It is one of the hardest blocks in the game.

The Diamond Method: If you have a Diamond or Netherite pickaxe, you can mine obsidian directly. You will need 10 blocks for a "budget" portal (without corners) or 14 blocks for a full frame. Note that mining a single block of obsidian takes approximately 9.4 seconds.
The Looting Method: Obsidian can often be found in chests within Bastion Remnants, Ruined Portals, or traded from Piglins in exchange for gold ingots.

2. Ignition Tools

Once the frame is built, it must be activated with fire.

Flint and Steel: Crafted by combining one Iron Ingot and one piece of Flint in any crafting grid. Flint is obtained by breaking gravel blocks (10% drop chance).
Fire Charge: A one-time use item crafted from Gunpowder, Blaze Powder, and Coal/Charcoal.
Natural Methods: If you lack these tools, you can place flammable blocks (like wood or wool) inside the frame and lead lava next to them, allowing the spreading fire to ignite the portal.

Standard Construction: Building the 4x5 Frame

The most common way to build a portal is by placing pre-mined obsidian blocks. The minimum exterior dimensions are 4 blocks wide and 5 blocks tall, creating a 2x3 hollow space in the center.

The Budget 10-Block Design

You do not need obsidian for the four corners of the rectangle. Most experienced players save resources by using "filler blocks" like cobblestone or dirt for the corners.

The Base: Place two obsidian blocks on the ground. Put a filler block on both ends.
The Pillars: On top of the two filler blocks, stack three obsidian blocks vertically on each side.
The Top: Place a filler block on top of each obsidian pillar, then connect them with two obsidian blocks in the middle.
Activation: Use your flint and steel on the top surface of the bottom obsidian blocks.

The Full 14-Block Design

If aesthetics are a priority, you can fill the corners with obsidian. This creates a solid purple-and-black monolith that looks more imposing in a base build. The mechanics remain identical to the 10-block version.

How to Make a Nether Portal Without a Diamond Pickaxe

Many speedrunners and advanced players enter the Nether within the first ten minutes of the game by using the "Lava Casting" method. This technique involves using buckets of lava and water to create obsidian directly in the shape of a portal frame, bypassing the need for diamonds.

Requirements for Casting

At least 2 Iron Buckets (one for water, one for lava).
A nearby lava pool (often found at y-levels below -54 or in surface lava lakes).
A stack of dirt or cobblestone to build the mold.

The Step-by-Step Casting Process

Find a Lava Pool: Locate a surface lava lake or a large pool deep underground. Ensure you have a "water bucket" ready to manage accidental fires.
Build a Backboard: Place a horizontal line of 4 blocks against the back of the lava pool.
Create the Base: Place a water source against a block so that it flows over the lava source blocks. Use your lava bucket to pick up lava and place it into the water stream at the base level. It will instantly turn into obsidian.
The "L" Shape Mold: To build the vertical pillars without the water washing away your lava, build a small pillar of dirt (3 blocks high) next to the portal spot and place a "water catcher" (a small 1x1 hole) at the top.
Casting the Pillars: Drop the water from the top so it flows down the side of your mold. Carefully place lava source blocks into the flowing water at the correct heights.
The Top Bridge: Construct a small bridge of dirt over the gap and use the same water-flow logic to cast the final two top blocks.
Drain the Water: Pick up the water source with your bucket, break the dirt mold, and your portal is ready to be lit.

Utilizing Ruined Portals

While exploring the Overworld, you will frequently encounter "Ruined Portals." These are naturally generated structures that are partially completed Nether portals.

How to Fix a Ruined Portal

Identify Crying Obsidian: Ruined portals often contain "Crying Obsidian"—a variant that drips purple particles. Important: Crying obsidian cannot be used to activate a portal. You must mine these out and replace them with regular obsidian.
Complete the Frame: Most ruined portals are missing 2 to 5 blocks. You can usually find extra obsidian in the nearby "Loot Chest." If not, you must mine or cast the remaining blocks.
Check the Loot: The chests near these portals often contain Gold nuggets, Flint and Steel, and even Enchanted Golden Apples, making them the most efficient way to enter the Nether early on.

What is the Maximum Size for a Nether Portal?

While 4x5 is the minimum, Minecraft allows for much larger portals. The maximum size for a functional Nether portal frame is 23x23 blocks. Huge portals are often used for:

Gold Farms: Larger portals increase the spawn rate of Zombified Piglins in the Overworld.
Map Art: Massive portals can serve as dramatic entryways to mega-bases.
Transporting Entities: It is much easier to push large mobs (like Ravagers or Ghasts) through a 10x10 portal than a cramped 2x3 opening.

Common Reasons a Nether Portal Won't Activate

If you have built the frame and used flint and steel but no purple vortex appears, check for these common errors:

Invalid Frame Material: Ensure there are no Crying Obsidian blocks in the frame.
Obstructions: There must be no blocks (including torches, tall grass, or snow layers) inside the hollow 2x3 area of the portal.
Incorrect Dimensions: Ensure the inner space is at least 2 blocks wide and 3 blocks tall. A 3x3 exterior (1x1 interior) will not work.
Corner Issues: While corners aren't required, you cannot leave a "gap" in the edges. The edges must be solid obsidian.

Understanding Portal Linkage and Coordinate Math

One of the most powerful features of the Nether is fast travel. The Nether and the Overworld are linked by a 1:8 coordinate ratio. This means every 1 block you travel in the Nether is equivalent to 8 blocks in the Overworld.

How to Link Portals Accurately

To ensure your Overworld portal connects to a specific location in the Nether:

Record your Overworld X and Z coordinates (Press F3 on Java Edition).
Divide both numbers by 8.
Build your second portal at those calculated X and Z coordinates in the Nether.
The Y coordinate (height) matters less but should ideally be similar to avoid spawning portals in dangerous lava ceilings or deep caves.

Nether Survival Tips for First-Time Visitors

Once you step into the purple vortex, your screen will swirl, and the Nether will load. Here is how to survive the first few minutes:

Bring Cobblestone: The Nether is made mostly of Netherrack, which Ghasts can easily destroy with their fireballs. Use cobblestone to build a small bunker around your portal so you don't get stranded.
Wear Gold: Piglins are neutral as long as you are wearing at least one piece of Golden Armor (boots or a helmet are cheapest).
Don't Sleep: Attempting to use a Bed in the Nether will cause a massive explosion. Use a Respawn Anchor fueled with Glowstone if you want to set a spawn point in this dimension.
Bring Extra Flint and Steel: A Ghast fireball can extinguish your portal. If you don't have a way to relight it, you could be trapped until you find materials in a fortress.

Summary of Building Methods

Method	Tool Required	Best For
Standard Mining	Diamond Pickaxe	Players with established mines and excess time.
Lava Casting	2 Iron Buckets	Speedrunners and early-game progression.
Ruined Portal	Varies	Lucky explorers who find a near-complete structure.
Piglin Bartering	Gold Ingots	Players already in the Nether needing a way out.

FAQ

Can a Nether portal be horizontal?

No. In the standard version of Minecraft, Nether portals must be built vertically. Horizontal portals (like End Portals) are not possible for the Nether.

Why did my portal spawn me in a different place on the way back?

This happens when the game cannot find a safe spot at the exact 1:8 coordinate match. It will place the portal at the nearest safe location, which can sometimes "break" the link. You will need to manually destroy the incorrectly placed portal and rebuild it at the precise coordinates.

How do I break a Nether portal?

You can deactivate a portal by breaking any of the obsidian blocks in the frame. Alternatively, you can place a bucket of water inside the frame (this only works in the Overworld) or cause an explosion (like a TNT block or a Ghast fireball) near the purple blocks.

Can I build a portal out of Crying Obsidian?

No. While Crying Obsidian is a beautiful block found near ruined portals, it lacks the magical properties required to hold the interdimensional rift. It is purely decorative or used for crafting Respawn Anchors.

What happens if I go through a portal with a horse?

Entities like horses, dogs, and even Minecarts can travel through portals. However, there is a "cooldown" period. After an entity passes through, it cannot go back through for a few seconds. Larger mobs may require a larger portal frame to fit through comfortably.

Building your first Nether portal is the gateway to the "mid-game" of Minecraft. Whether you mine the obsidian slowly or cast it heroically with lava buckets, entering the red wastes of the Nether opens up a world of potion-brewing, fast travel, and ultimate gear upgrades. Always remember to bring a way to relight your portal, and never, ever try to sleep in the Nether.