A redstone repeater is a control block that does three jobs at once for redstone wiring. It pushes a fading signal back up to full strength, it delays that signal by a set amount of time, and it forces the current to flow in one direction only.
If you have ever run a line of redstone dust across a long floor and watched it die before it reached the lever you wanted, the repeater is the fix. It is also the block that makes timed circuits, clocks, and piston doors possible.
Repeaters are cheap to craft and easy to use once the direction and delay make sense. A few of them turn a flat redstone line into a real circuit.
What a redstone repeater does
Redstone dust loses one level of signal strength for every block it travels. A signal starts at strength 15 and drops to 0 after 15 blocks, so plain dust cannot carry power any further than that. A repeater placed in the line reads the incoming signal and sends out a fresh signal at full strength 15. Drop a repeater every 15 blocks or fewer and a redstone line can run as far as you want.
The second job is delay. Every repeater holds the signal for a short beat before passing it on. You can set that beat to one, two, three, or four redstone ticks. One redstone tick is 0.1 seconds, so the delay runs from 0.1 to 0.4 seconds per repeater. Chain several together and the delays add up, which is how players build timers.
The third job is direction. A repeater is a diode: power goes in the back and out the front, never the other way. This stops a signal from feeding back into a circuit and causing flicker or unwanted triggers.
How to craft a redstone repeater
You craft a redstone repeater on a crafting table. The recipe makes one repeater and needs:
- 2 redstone torches
- 1 redstone dust
- 3 stone
Set the ingredients in the crafting grid like this: the middle row holds a redstone torch, a piece of redstone dust, and a second redstone torch, in that order. The bottom row is three blocks of stone. Leave the top row empty.
The stone has to be smelted stone, not cobblestone. If the recipe is not showing up, smelt cobblestone in a furnace first to turn it into stone. Redstone torches are cheap to make on their own: one redstone dust on top of one stick gives you a torch.
A crafting table is the normal way to get a repeater, so keep a stack of redstone handy when you mine. Redstone dust comes from mining redstone ore, which is common below Y level 16.
How to place and aim a repeater
A repeater sits flat on top of a block. It cannot stand upright or hang from a ceiling, so every redstone signal that passes through a repeater travels horizontally. You can place a repeater on most solid blocks, and modern versions also let it rest on glass, upside-down slabs, and other surfaces with a flat top.
When you place a repeater it faces away from you. Look at the arrow printed on the top of the block. The arrow points in the direction the signal will travel. Power enters the flat back edge and leaves the front edge where the arrow points. Line the arrow up with the lever, button, or component you want to reach.
If a repeater seems dead, the first thing to check is its direction. A repeater placed backward will never pass a signal, because power cannot enter the front.
Setting the delay
Two small redstone torches sit on top of every repeater. The gap between them shows the current delay setting. Right-click the repeater to slide the movable torch one notch further back. Each right-click steps the delay up by one redstone tick, and after the fourth setting it loops back to the first.
The four settings are 1, 2, 3, and 4 redstone ticks, equal to 0.1, 0.2, 0.3, and 0.4 seconds. Even the shortest setting adds a real delay, so a repeater always slows a signal down a little. That tiny built-in delay is useful: it is what lets you stagger pistons or build a repeater clock.
To build a longer timer, place several repeaters in a row and add up their delays. Four repeaters at the 4-tick setting give 1.6 seconds of delay in a single line.
Locking a repeater
A repeater can be locked, which freezes its output at whatever value it currently holds. To lock one, point a second repeater or a comparator into its side so the side block powers it. While that side signal stays on, the locked repeater ignores its own input and keeps its output fixed.
This is the simplest way to store one bit of information in redstone. A locked repeater holds an “on” or “off” state until you unlock it, which makes it the core of latches and memory cells. Many compact piston doors and combination locks use a locked repeater somewhere in the wiring.
Powering blocks with a repeater
A repeater does more than carry a signal through dust. When a repeater points directly into a solid block, it strongly powers that block. A strongly powered block can then power redstone dust sitting on top of it or next to it, and it can trigger any component attached to it.
Plain redstone dust only weakly powers the block beneath it, and a weakly powered block cannot pass power on to other dust. This difference makes the repeater a clean way to send a signal up a wall or into a block you want to use as a power source.
Common mistakes to avoid
The most common mistake is facing the repeater the wrong way. Always check the arrow before you wire anything else.
The second is forgetting the delay. If a circuit fires later than you expect, count your repeaters and their settings. Each one adds at least 0.1 seconds.
A third trap is trying to power a repeater from the front or the side with dust. Dust laid against the front does nothing, and dust against the side does nothing either. Only the back accepts an input signal. Side inputs work only for the locking trick, and only from another repeater or a comparator.
Players also mix up the repeater with the redstone comparator. The two blocks look similar, but a comparator has three torches instead of two and does a different job. A comparator measures and compares signals; a repeater extends and delays them.
Java and Bedrock differences
A redstone repeater works the same way in Java and Bedrock Edition. The crafting recipe, the four delay settings, the diode behavior, and the locking trick are identical on both. The only gaps show up in frame-perfect contraptions, where the two editions process redstone updates in a slightly different order. For ordinary doors, farms, and clocks, you can follow the same steps on either edition.
Frequently asked questions
How do you change the delay on a redstone repeater?
Right-click the repeater. Each click moves the delay up one step through 1, 2, 3, and 4 ticks, then loops back to 1. The gap between the two torches on top shows the current setting.
How far does redstone travel before you need a repeater?
Redstone dust carries a signal 15 blocks before it fades to nothing. Place a repeater at or before that 15-block limit to reset the signal to full strength and keep the line going.
Can a redstone repeater power a block?
Yes. A repeater pointed into a solid block strongly powers it, so that block can pass power to redstone dust or components around it. Plain redstone dust cannot do this.
What is the difference between a repeater and a comparator?
A repeater extends a signal, delays it, and forces one-way flow. A comparator compares two signals, can subtract one from the other, and can read how full a container is. A comparator also has three torches on top, while a repeater has two.
Can you place a redstone repeater on glass?
Yes. Modern versions of Minecraft let you place a repeater on glass and on most other blocks with a flat top surface, including upside-down slabs.
Why is my redstone repeater not working?
Check three things: the arrow direction, whether the repeater is locked by a side signal, and whether the input is actually reaching the back of the block. A backward repeater is the usual culprit.
Does a redstone repeater always output a full signal?
Yes. As long as the input is any strength above 0, the repeater outputs a signal at full strength 15. That steady output is what makes it work as a signal extender.
Getting more out of the repeater
Once you are comfortable aiming a repeater and reading its delay, most redstone builds open up. A good next step is to wire two locked repeaters against each other and watch how a simple memory cell holds its state long after the button is released.