Overview
A comparator is the block that lets redstone read the world rather than just switch it. In its default compare mode it passes the signal from behind unless a side input is stronger, in which case it outputs nothing; click it once and the front torch lights, switching it to subtract mode, where it outputs the rear signal minus the strongest side signal. That arithmetic is useful, but the real reason comparators are everywhere is measurement. Put one against a container and it outputs a signal proportional to how full that container is — a chest, a hopper, a furnace, a brewing stand, a barrel, a shulker box. Point it at other things and it reads them too: a cauldron's water level, a composter's progress, how many slices are left on a cake, which page a lectern is open at, the rotation of an item in an item frame, whether a jukebox is playing and which disc, the charge on a respawn anchor, how many mobs a beehive holds. Item-sorting systems, auto-smelters, farm-full detectors and hidden item-frame door codes are all built on comparator readings.
Reading how full a container is for sorting systems and farm shut-offs, doing subtraction in a circuit, and turning item frames, lecterns and cauldrons into hidden switches.
Redstone Comparator is a redstone block in Minecraft Java Edition 1.21.4. Redstone Comparator is made at a crafting table. A hardness of 0 means it is one of the quicker blocks to clear.
No specific tool is required to collect it. Broken correctly, it drops itself. It offers almost no protection from explosions (0 blast resistance).
A full stack holds 64. It is crafted from Redstone Torch, Nether Quartz, and Stone. Nothing on the crafting grid is made from it.
How to get it
Craft it from 3 stone, 3 redstone torches and 1 nether quartz. The quartz means a Nether trip, but nether quartz ore needs only a wooden pickaxe and is common between Y 10 and Y 117.
Tips
- Click it to toggle subtract mode; the small front torch lit means subtract, unlit means compare.
- A comparator against a container outputs 1 to 15 depending on fill, which is how every item sorter detects a full slot.
- An item frame rotated 1 of 8 positions outputs 1 to 8 through a comparator — that is the classic hidden door lock.
- Read redstone basics before wiring a sorter; comparator signal strength is not intuitive at first.
Properties
With 0 blast resistance Redstone Comparator goes down to any nearby explosion. It is fully opaque and produces no light. Stack size is 64 — the standard full stack.
- Transparent
- No
- Required tool
- Any
Crafting recipe
Crafting Table
Redstone Comparator
Drops
Mined with any, Redstone Comparator drops itself.
Guides and tools that cover this
Frequently asked questions
How do you get Redstone Comparator in Minecraft?
Redstone Comparator is crafted from Redstone Torch, Nether Quartz, and Stone.
What tool do you need to break Redstone Comparator?
No specific tool is required — Redstone Comparator can be broken by hand.
Is Redstone Comparator blast resistant?
Redstone Comparator has a blast resistance of 0, so an explosion nearby will destroy it.
How many Redstone Comparator fit in one stack?
Redstone Comparator stacks to 64, which puts 3,456 of them in a double chest.
