Minecraft:Observer

Template:Infobox block An observer is a Minecraft:block that emits a quick Minecraft:redstone pulse from its back whenever its "face" detects that the Minecraft:block, Minecraft:fluid, or Minecraft:air directly in front of it has changed.

Obtaining

Breaking

An observer requires a Minecraft:pickaxe to be mined. When mined without a pickaxe, it drops nothing. Template:Breaking row

Usage

An observer is placed similarly to a Minecraft:piston. It observes the block that it is placed against. The texture of the detecting side is that of an observing face. As observers can detect the state of other observers, placing two adjacent observers, each watching the other, can make a fast and compact redstone clock. They send out a Minecraft:redstone pulse.

Behavior

Template:IN, an observer detects shape updates coming from the block it's facing. This can involve changes in block states (like crops growing, for example), or the breaking or placing of a block. This makes observers differ from block update detectors in terms of what they can detect.Template:Only

Template:IN, an observer acts as a block update detector and detects anything that causes a block update.

The causes and propagation of block updates are different between Java Edition and Bedrock Edition. As a result, each can detect some kinds of changes that the other cannot. See the table below for a comparison.

When it detects something, the observer emits a Minecraft:redstone pulse of strong power at signal strength 15 for 2 Minecraft:game ticks. The pulse can power Minecraft:redstone dust, a Minecraft:redstone comparator, a Minecraft:redstone repeater, or any mechanism component located at its opposite end.

In Java Edition, the pulse is emitted with a delay of 2 game ticks. In Bedrock Edition, it is delayed by 2 game ticks as well, but it's sometimes delayed by 4 or 6 game ticks due to Template:Bug, a bug causing redstone delays to be incorrect when components are activated by world changes (which, in the case of the observer in Bedrock Edition, is the only way it can be activated), as opposed to pure redstone components ticking. Its timing can also be incorrect due to Template:Bug.

Observers also emit a pulse after getting moved by Minecraft:pistons: this enables them to be used in Minecraft:flying machines. Template:IN, however, moving an observer that is currently emitting a redstone signal will cause it to turn off instead.

Because observers in Java Edition react to shape updates, they can detect some changes that a Minecraft:block update detector (BUD) would be unresponsive to, as opposed to Bedrock Edition where observers detect the exact same updates that any other BUD would detect.

An observer preventing the redstone signal from being transmitted.

Observers preventing the redstone signal from being transmitted in Java Edition

Observers are visually opaque and non-Minecraft:conductive: they block light and allow mob spawning on top, do not cut off redstone wire, and cannot conduct redstone power. Template:IN, they also allow opening chests below and prevent redstone wire placed on it from transmitting a signal downward.

Limitations

Block change	Detected in
	Template:El	Template:El
Template:BlockSprite A Minecraft:block or a Minecraft:fluid being placed or broken in any way; either directly by Minecraft:player, Minecraft:enderman, or Minecraft:ravager or through: Placing/breaking two-block-tall/wide blocks Minecraft:Snow golem or Minecraft:snowfall creating Minecraft:snow Snow melting Minecraft:Dispenser placing Minecraft:carved pumpkin, Minecraft:wither skeleton skull, Minecraft:shulker box, or Minecraft:dyed shulker box Creating/removing Minecraft:fluid using player or dispenser Placing Minecraft:scaffolding on top/side of another scaffolding Minecraft:Entities on Minecraft:fire touching Minecraft:powder snow, causing it to melt Block being broken by fluid, (sticky) Minecraft:piston, Minecraft:explosion, or Minecraft:opacity,<ref>For example, a Minecraft:button attached to a block, when breaking the block, that button breaks and causes block update that can be detected by observer.</ref> Inconsistent Minecraft:light level<ref>For example, a Minecraft:mushroom are on light level of 13, according to the Minecraft Wiki, at level 13 and above, mushroom uproots unless on Minecraft:mycelium, Minecraft:podzol, or Minecraft:nylium. When the mushroom is updated, that mushroom breaks and causes a block update that can be detected by observer.</ref><ref>Another example, a Minecraft:wheat crop uproots at level 0 or below. When updating the wheat, that wheat breaks and causes a block update that can be detected by observer.</ref> Flammable blocks getting burned up by Minecraft:fire or Minecraft:lava A Minecraft:falling block turning into a Minecraft:falling block entity and vice versa Minecraft:Cactus breaking either by placing a Minecraft:solid block next to it, or by placing a Minecraft:fluid on top of it<ref>While it's not possible to set this up normally (since the observer has to place on the side of the cactus (because the top and the bottom are already occupied by the Minecraft:fluid and the block that supports the cactus (like sand) relatively), which causes the cactus to break), it's possible to reproduce this using the Template:Cmd command.Template:Verify</ref> Minecraft:Villager planting and destroying crops Minecraft:Zombie breaking Minecraft:doors Minecraft:Leaves decaying Chorus plant break due to their invalid placement<ref>For example, places 2 chorus plants on top of an Minecraft:end stone, and when a chorus plant is placed on the side of the bottom one, that "bottom" chorus plant breaks and causes block update, which can be detected by the observer.</ref> Using up a Minecraft:damaged anvil, causing the damaged anvil to break Fully eating a cake Minecraft:Water touching a Minecraft:sponge, causing the area near the sponge to be removed and create a block update to the water A wither rose block being planted after wither kills a mob if the block is Minecraft:grass block, Minecraft:dirt, Minecraft:coarse dirt, Minecraft:moss block, Minecraft:mud, Minecraft:soul sand, Minecraft:soul soilTemplate:Only, or Minecraft:netherrack Left-clicking the Minecraft:dragon egg, causing it to teleport and create a block update at the starting teleporting point and the teleporting destination of the dragon egg Minecraft:Boat and Minecraft:boat with chest breaking a Minecraft:lily pad Minecraft:Turtle laying Minecraft:turtle egg(s), trampling an eggs=1 Minecraft:turtle egg or turtle egg(s) hatching into baby turtle(s) Damaging a Minecraft:silverfish, causing a nearby Minecraft:infested block to turn into a silverfish and create a block update Minecraft:Frog laying Minecraft:frogspawn or frogspawn hatching into Minecraft:tadpole Thrown Minecraft:trident breaks Minecraft:pointed dripstone Minecraft:Sniffer egg hatching into Minecraft:snifflet The spawning of the upper part of the pitcher crop that has the block state age change to 2	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Water being inserted to or removed from a block that can be Minecraft:waterlogged.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A Minecraft:water (or Minecraft:lava, if the Minecraft:game rule lavaSourceConversion is set to trueTemplate:Only) source block being created by having 2 water source blocks unite to each other.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Minecraft:Fire being ignited or extinguished in any way; either directly by player or through: A dispenser Fire spreading to flammable blocks next to Minecraft:lava or fire Minecraft:Fireball from a dispenser, a Minecraft:ghast, or a Minecraft:blaze Minecraft:Lightning A Minecraft:bed or a Minecraft:respawn anchor exploding Placing an Minecraft:end crystal on Minecraft:bedrock or Minecraft:obsidian in Minecraft:the End Being extinguished by Minecraft:fluid, Minecraft:splash water bottle, Minecraft:lingering water bottle, or naturally	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:fire is turned into a Minecraft:soul fire (but not vice versa).	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Minecraft:Fluid or Minecraft:powder snow being placed in or removed from a Minecraft:cauldron or the level of the Minecraft:water/lava/powder snow cauldron changing in any way, for example using Minecraft:bucket (empty, water, Minecraft:lava, powder snow), Minecraft:glass bottle, Minecraft:water bottle, Minecraft:rain, Minecraft:snowfall, Minecraft:pointed dripstone, burning Minecraft:entity on water/powder snow cauldron.	Template:Tc	Template:Tc
A block being replaced by Template:Cmd, Template:Cmd, or Template:Cmd commands.	Template:Tc	Template:Tc<ref>Will be detected without the strict argument, will not with the strict argument.</ref>
Template:ItemSprite Changing the Minecraft:block state of a block using a Minecraft:debug stick.Template:Only	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:nether portal being created.	Template:Tc	Template:Tc<ref>Template:Bug</ref>
Template:BlockSprite A Minecraft:nether portal being destroyed.	Template:Tc<ref>Template:Bug</ref>	Template:Tc
Template:BlockSprite An Minecraft:end portal being created.	Template:Tc	Template:Tc
Template:BlockSprite An Minecraft:end portal being destroyed.	Template:Tc	Template:Tc<ref>Template:IN removing an Minecraft:end portal frame block won't destroy the portal.</ref>
Template:EntitySprite Template:EntitySprite Template:EntitySprite The creation of an Minecraft:iron golem, a Minecraft:snow golem or a Minecraft:wither.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A (sticky) Minecraft:piston (head) extending or retracting.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A block being pushed or pulled by a (sticky) Minecraft:piston; either directly or stuck to Minecraft:slime block or Minecraft:honey block moved by the piston.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:monster spawner block activating.	Template:Tc	Template:Tc
Template:BlockSprite The mob spawn of a Minecraft:monster spawner being changed using a Minecraft:spawn egg.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Activation or deactivation of Minecraft:trial spawner or Minecraft:ominous trial spawner.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Opening and closing of Minecraft:vault or Minecraft:ominous vault.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A (trapped) Minecraft:chest turns into a large (trapped) chest and vice versa.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite A Minecraft:chest, a Minecraft:trapped chest, or an Minecraft:ender chest opening or closing.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A Minecraft:shulker box opening or closing.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:barrel opening or closing.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite An item being moved in or out of a Minecraft:chest, Minecraft:trapped chest, Minecraft:barrel, or Minecraft:shulker box.	Template:Tc	Template:Tc
Template:BlockSprite The Minecraft:inventory of any other container changing.	Template:Tc	Template:Tc
Template:BlockSprite The crack stage of an Minecraft:anvil changing after use.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:snow layer being added into snow by Minecraft:player or by Minecraft:snowfall.<ref>Template:IN the Minecraft:game rule snowAccumulationHeight must be larger than Template:Cd.</ref>	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:beacon activating or deactivating.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:command block producing a success.	Template:Tc	Template:Tc
Template:BlockSprite The unconditional/conditional stage of a command block changing.	Template:Tc	Template:Tc
Template:BlockSprite The impulse/chain/repeat stage of a command block changing.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockLink A piece of a Minecraft:cake or a Minecraft:cake with candles changing.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:hopper being activated or deactivated. (Turning the hopper on/off)	Template:Tc	Template:Tc
Template:BlockSprite Dry Minecraft:farmland changing between its six dry-looking hydration stages.	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Farmland changing between dry and humid or vice versa.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A Minecraft:dispenser or a Minecraft:dropper activating or deactivating.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A (deepslate) Minecraft:redstone ore block activating or deactivating.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Minecraft:Grass block or Minecraft:mycelium turning to Minecraft:dirt or Minecraft:nylium to Minecraft:netherrack after being spread using Minecraft:bone meal or grass block or mycelium decaying to dirt or nylium into netherrack.	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Coarse dirt or Minecraft:rooted dirt converting into Minecraft:dirt through the use of a Minecraft:hoe.	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Grass block, Minecraft:dirt, or Minecraft:dirt path converting into Minecraft:farmland through the use of a Minecraft:hoe.	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Grass block, Minecraft:podzol, Minecraft:mycelium, Minecraft:dirt, Minecraft:coarse dirt, or Minecraft:rooted dirt converting into Minecraft:dirt path through the use of a Minecraft:shovel.	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Farmland or Minecraft:dirt path converting into dirt.	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Concrete powder converting into Minecraft:concrete, either through direct contact with Minecraft:water, or entering water as a Minecraft:falling block.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:sea pickle being added into a colony of sea pickles.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:pink petal being added into a group of pink petals.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:turtle egg being added into a cluster of turtle eggs.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:turtle egg being removed from a cluster of turtle eggs by breaking or trampling.	Template:Tc	Template:Tc
Template:BlockSpriteTemplate:BlockSprite The hatch Minecraft:block state of a Minecraft:turtle egg and a Minecraft:sniffer egg changing.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:stone, Minecraft:cobblestone, Minecraft:deepslate, or any Minecraft:stone brick variant block being turned into an Minecraft:infested block by Minecraft:silverfish.	Template:Tc	Template:Tc
Template:BlockSprite A double Minecraft:slab being created by adding a slab into another slab.	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Ice melting into Minecraft:water or water freezing into ice.	Template:Tc	Template:Tc
Template:BlockSprite Water freezing into Minecraft:frosted ice through the use of Minecraft:Frost Walker or frosted ice melting into water.	Template:Tc	Template:Tc
Template:BlockSprite Turn Minecraft:pumpkin into Minecraft:carved pumpkin using Minecraft:shears.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite Turn Minecraft:logs/Minecraft:woods/stems/Minecraft:hyphae/Minecraft:block of bamboo into Minecraft:stripped logs/woods/stems/hyphae/Minecraft:block of stripped bamboo using Minecraft:axes.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite The stage of a Minecraft:sapling or Minecraft:bamboo changing.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite The age of Minecraft:mangrove propagules, Minecraft:bamboo, Minecraft:wheat, Minecraft:carrots, Minecraft:potatoes, Minecraft:beetroots, Minecraft:melon stem, Minecraft:pumpkin stem, Minecraft:nether wart, Minecraft:cocoa, Minecraft:sweet berry bush, Minecraft:chorus flower, Minecraft:cactus, Minecraft:sugar cane, Minecraft:kelp, Minecraft:weeping vines, Minecraft:twisting vines, Minecraft:cave vines, Minecraft:fire, Minecraft:frosted ice, Minecraft:torchflower crop, or Minecraft:pitcher crop changing.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:torchflower crop turning into a Minecraft:torchflower.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Minecraft:Fluid flowing into the empty space to or draining from a block.<ref>When the fluid source block is removed, all of the fluid flowing from the source is removed and causes a block update.</ref>	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Minecraft:Fluid, Minecraft:light block, or Minecraft:composter level changing.	Template:Tc	Template:Tc
Template:BlockSprite (Flowing) Minecraft:water turning into Minecraft:stone through contact with Minecraft:lava.	Template:Tc	Template:Tc
Template:BlockSprite Flowing lava turning into Minecraft:cobblestone through contact with water.	Template:Tc	Template:Tc
Template:BlockSprite Lava turning into Minecraft:obsidian through contact with water.	Template:Tc	Template:Tc
Template:BlockSprite (Flowing) lava turning into Minecraft:basalt through contact with Minecraft:soul soil and Minecraft:blue ice.	Template:Tc	Template:Tc
Template:BlockSprite Water turning into Minecraft:bubble column or vice versa.	Template:Tc	Template:Tc
Template:BlockSprite Upward bubble column turning into whirlpool bubble column or vice versa.	Template:Tc	Template:Tc
Template:BlockSprite An Minecraft:eye of ender being inserted into an Minecraft:end portal frame.	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Player or Minecraft:villager sleeping/waking up in a Minecraft:bed.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite A Minecraft:grass block, a Minecraft:mycelium, or a Minecraft:podzol block becoming snowy or not snowy.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Text in a Minecraft:sign or a Minecraft:hanging sign being edited.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A dye or glow being applied to a sign or a hanging sign or removed from it.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Waxing a Minecraft:sign or a Minecraft:hanging sign using a Minecraft:honeycomb.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite The mode of a Minecraft:structure block or a Minecraft:comparator changing.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite A Minecraft:grass block, Minecraft:short grassTemplate:Only or Minecraft:fernTemplate:Only being grazed by a Minecraft:sheep.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:carrot crop being eaten by a Minecraft:rabbit.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:button being pressed or returning to inactive state.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A Minecraft:pressure plate or the Minecraft:detector rail activating or returning to inactive state.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite The power of a Minecraft:weighted pressure plate, Minecraft:redstone wire, Minecraft:daylight detector, or Minecraft:target changing.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:lever being flicked.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A Minecraft:redstone lamp or a Minecraft:redstone torch lighting up or turning off.	Template:Tc	Template:Tc
Template:BlockSprite The mode of Minecraft:daylight detector being changed.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:TNT igniting.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite Minecraft:Coral/Minecraft:coral block/Minecraft:coral fan converting into Minecraft:dead coral/Minecraft:dead coral block/Minecraft:dead coral fan.	Template:Tc<ref>Template:IN, the death of a coral fan cannot happen under normal circumstances — it happens the next tick after the coral fan is placed, so the observer has already read the placement or water removal update, and coral fans placed using commands are waterlogged — but if lag is used to make the unwaterlogging and death events happen separately, the observer detects both. For coral, the death also happens too fast for the observer to detect it separate from the placement or water removal, but a non-waterlogged coral can be placed using commands. Coral blocks take multiple seconds to die, and removing water next to the coral block does not activate the observer anyway, so they can be detected under normal circumstances.</ref>	Template:Tc
Template:BlockSprite A Minecraft:sponge turning into a Minecraft:wet sponge.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:wet sponge drying into a Minecraft:sponge in Minecraft:the Nether.<ref>This event cannot normally happen, but if Minecraft:commands are used to place a wet sponge in the Nether, the sponge dries when it receives a random tick.</ref>	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:door being opened or closed by a Minecraft:player, a Minecraft:villager, a Minecraft:piglin, a Minecraft:piglin brute, a Minecraft:vindicatorTemplate:Only, a Minecraft:wandering traderTemplate:Only, or Minecraft:redstone.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:trapdoor being opened or closed by a Minecraft:player or Minecraft:redstone.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:fence gate being opened or closed by a Minecraft:player or Minecraft:redstone.	Template:Tc	Template:Tc
Template:BlockSprite The in_wall Minecraft:block state of a Minecraft:fence gate changing.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite A Minecraft:furnace, a Minecraft:blast furnace, or a Minecraft:smoker lighting up or turning off.	Template:Tc	Template:Tc
Template:BlockSprite The distance of Minecraft:leaves from the closest Minecraft:log changing.	Template:Tc	Template:Tc
Template:BlockSprite The distance of a Minecraft:scaffolding from the closest supporting block changing.	Template:Tc	Template:Tc
Template:BlockSprite The bottom Minecraft:block state of a Minecraft:scaffolding changing.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:potion being moved in or out of a Minecraft:brewing stand.	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Book and quill or Minecraft:written book being moved in or out of a Minecraft:lectern.	Template:Tc	Template:Tc
Template:BlockSprite The note of a Minecraft:note block being changed.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:note block being left-clicked in Minecraft:Survival mode.	Template:Tc	Template:Tc
Template:BlockSprite The instrument Minecraft:block state of a Minecraft:note block changing.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:music disc being inserted to or removed from a Minecraft:jukebox by Minecraft:player, Minecraft:hopper, or Minecraft:minecart with hopper.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:redstone repeater locking or unlocking.	Template:Tc	Template:Tc
Template:BlockSprite The delay of a Minecraft:redstone repeater being changed.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite A Minecraft:redstone repeater, a Minecraft:redstone comparator, an observer, a Minecraft:note block, a Minecraft:lectern, a Minecraft:lightning rod, an Minecraft:activator rail, a Minecraft:powered rail, a Minecraft:sculk sensor<ref group="n" name="Sensor">When deactivated, the sculk sensor's and the calibrated sculk sensor's "sculk_sensor_phase" block stage is converted from "active"->"cooldown"->"inactive". This means that a deactivating sculk sensor actually triggers an observer twice in a row.</ref>, a Minecraft:calibrated sculk sensor<ref group="n" name="Sensor"/>, a Minecraft:tripwire, or a Minecraft:tripwire hook activating or deactivating.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A Minecraft:tripwire or a Minecraft:tripwire hook attaching or detaching.	Template:Tc	Template:Tc
Template:BlockSprite The disarmedTemplate:Only or disarmed_bitTemplate:Only Minecraft:block state of a Minecraft:tripwire changing.<ref>The disarmedTemplate:Only or disarmed_bitTemplate:Only block state cannot change without also detaching the tripwire, so this event cannot happen in isolation.</ref>	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Sculk shrieker starting shrieking.	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Sculk shrieker stopping shrieking.	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Sculk catalyst blooming or unblooming.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A Minecraft:dragon head or a Minecraft:piglin head activating or deactivating.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite A Minecraft:player head, a Minecraft:zombie head, Minecraft:creeper head, a Minecraft:skeleton skull, or a Minecraft:wither skeleton skull getting powered or depowered.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:conduit activating.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:conduit deactivating.	Template:Tc	Template:Tc
Template:ItemSprite An Minecraft:item frame being placed or an item being added to, rotated in or removed from an item frame.	Template:Tc	Template:Tc
Template:BlockSprite Something being teleported by an Minecraft:end gateway.	Template:Tc	Template:Tc
Template:BlockSprite An item being inserted to or removed from a Minecraft:flower pot.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite The shape or rotation of Minecraft:walls, Minecraft:fences, Minecraft:iron bars, Minecraft:glass panes, Minecraft:stairs, Minecraft:tripwire, Minecraft:redstone, Minecraft:vines, Minecraft:mushroom blocks, Minecraft:mushroom stem, Minecraft:fire, all type of Minecraft:rails, Minecraft:glow lichen, Minecraft:sculk vein, Minecraft:pointed dripstone, or chorus plant changing.	Template:Tc	Template:Tc
Template:BlockSprite The top Minecraft:block state of the Minecraft:walls changing.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A Minecraft:melon/Minecraft:pumpkin created from a melon stem/pumpkin stem.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite The Minecraft:stem of a Minecraft:melon or Minecraft:pumpkin attaching or detaching.	Template:Tc<ref>Template:IN, placing a pumpkin or melon next to a corresponding stem does not cause the stem to attach.</ref>	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Minecraft:Kelp/Minecraft:weeping vines/Minecraft:twisting vines/Minecraft:cave vines turning into a Minecraft:kelp/Minecraft:weeping vines/Minecraft:twisting vines/Minecraft:cave vines plant or vice versa.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite The berries Minecraft:block state of the Minecraft:cave vines (plant) changing.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A Minecraft:campfire being lit or extinguished.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Minecraft:Food being cooked or popping out of a campfire.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A Minecraft:hay bale being placed or removed below a campfire.	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Glowstone being added into a Minecraft:respawn anchor.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:respawn anchor being used.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:lodestone being used.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Oxidation level of unwaxed Minecraft:block of copper or Minecraft:cut copper block, Minecraft:slab, Minecraft:stairs, Minecraft:chiseled, Minecraft:copper grate, Minecraft:bulb, Minecraft:door, or Minecraft:trapdoor changing.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Minecraft:block of copper or Minecraft:cut copper block, Minecraft:slab, Minecraft:stairs, Minecraft:chiseled, Minecraft:copper grate, Minecraft:bulb, Minecraft:door, or Minecraft:trapdoor being waxed or unwaxed.	Template:Tc	Template:Tc
Template:BlockSprite Activation and deactivation of Minecraft:creaking heart.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite Minecraft:Grass/Minecraft:fern/Minecraft:seagrass turning into Minecraft:tall grass/Minecraft:large fern/tall seagrass after Minecraft:bone meal is used on it.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Minecraft:Cactus, Minecraft:sugar cane, Minecraft:bamboo, Minecraft:bamboo shoot, Minecraft:vines, Minecraft:weeping vines, Minecraft:twisting vines, Minecraft:kelp, Minecraft:cave vines, Minecraft:pointed dripstone, or Minecraft:chorus flower growing.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Opening and closing of Minecraft:eyeblossom.	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Chorus flower growing or leaving a Minecraft:chorus plant behind and causing a block update to that.	Template:Tc	Template:Tc
Template:BlockSprite An Minecraft:amethyst cluster growing.<ref>From nothing to small to medium to large and finally to cluster.</ref>	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:bamboo shoot turning into Minecraft:bamboo.	Template:Tc	Template:Tc
Template:BlockSprite The leaves Minecraft:block state of Minecraft:bamboo changing.	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Mushroom spreading.	Template:Tc	Template:Tc
Template:BlockSprite 1-block-tall Minecraft:flowers spreading after Minecraft:bone meal is used on one.Template:Only	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Glow lichen spreading after Minecraft:bone meal is used on one.	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Moss blocks spreading after Minecraft:bone meal is used on one.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:big dripleaf increasing or decreasing its tilt.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:big dripleaf turning into a big dripleaf stem.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:big dripleaf growing after Minecraft:bone meal is used on it.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:small dripleaf turning into a Minecraft:big dripleaf after Minecraft:bone meal is used on it.	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Hanging roots being created underneath Minecraft:rooted dirt after Minecraft:bone meal is used on it.	Template:Tc	Template:Tc
Template:BlockSprite A hanging Minecraft:mangrove propagule being created underneath Minecraft:mangrove leaves after Minecraft:bone meal is used on it.	Template:Tc	Template:Tc
Template:BlockSprite The number of Minecraft:sea pickle(s) changing after Minecraft:bone meal is used on a Minecraft:coral block.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:sea pickle being created after Minecraft:bone meal is used on a Minecraft:coral block.Template:Only	Template:Tc<ref>Template:IN, using bone meal on a coral block does not create sea pickles, due to Template:Bug.</ref>	Template:Tc
Template:BlockSprite Using Minecraft:bone meal on Minecraft:pink petals that do not already have 4 petals.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Template:BlockSprite Vegetation<ref>Includes Minecraft:short grass, Minecraft:tall grass, 1-block-tall Minecraft:flowers, Minecraft:seagrass, tall seagrass, Minecraft:coral, (wall) Minecraft:coral fan, Minecraft:moss carpet, Minecraft:azalea, Minecraft:flowering azalea, Minecraft:crimson roots, Minecraft:warped roots, Minecraft:Nether fungus, Minecraft:Nether sprouts, Minecraft:twisting vine, and Minecraft:pink petals.</ref> growing on top of or inside Minecraft:grass block, Minecraft:water, Minecraft:moss block, or Minecraft:nylium after Minecraft:bone meal is used on one.	Template:Tc	Template:Tc
Template:EnvSprite A Minecraft:sapling or a Minecraft:propagule turning into a Minecraft:tree.	Template:Tc	Template:Tc
Template:EnvSprite A Minecraft:mushroom turning into a Minecraft:huge mushroom after Minecraft:bone meal is used on it.	Template:Tc	Template:Tc
Template:EnvSprite An Minecraft:azalea turning into an Minecraft:azalea tree after Minecraft:bone meal is used on it.	Template:Tc	Template:Tc
Template:EnvSprite A Minecraft:Nether fungus turning into a Minecraft:huge fungus after Minecraft:bone meal is used on it.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:grass block turning into Minecraft:dirt when a Minecraft:sapling grows into a tree on that Minecraft:grass block.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:grass block/Minecraft:dirt turning into Minecraft:podzol<ref>Applies to the block under the sapling and the area around the sapling.</ref> when a 2×2 Minecraft:spruce sapling grows into a tree on that grass block/dirt.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:grass block/Minecraft:dirt or any other blocks turning into Minecraft:rooted dirt by when an Minecraft:azalea or a Minecraft:flowering azalea grows on that grass block/dirt.	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Mud turning into Minecraft:muddy mangrove roots when a Minecraft:mangrove tree grows.	Template:Tc	Template:Tc
Template:BlockSprite A block that has sculk_replaceable tag turning into Minecraft:sculk by Minecraft:sculk catalyst.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:sculk vein/sculk veins being created by sculk catalyst.	Template:Tc	Template:Tc
Template:BlockSprite The shape of sculk vein(s) changing by sculk catalyst.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A Minecraft:sculk sensor or a Minecraft:sculk shrieker being created by sculk catalyst.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:bell ringing.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:bell getting powered by a redstone signal.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:bell getting depowered.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A Minecraft:bee leaving a Minecraft:bee nest or a Minecraft:beehive.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A Minecraft:bee entering a Minecraft:bee nest or a Minecraft:beehive (thus increasing the honey level).	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite The Minecraft:honey being collected from a bee nest or a beehive using Minecraft:shears or a Minecraft:glass bottle.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A (dyed) Minecraft:candle being added into a (dyed) candle.	Template:Tc	Template:Tc
Template:BlockLink A candle being added into a Minecraft:cake.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite Template:BlockLink A candle, Minecraft:dyed candle, or candle cake being lit or extinguished.	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Dirt/Minecraft:coarse dirt/Minecraft:rooted dirt turning into Minecraft:mud through the use of a Minecraft:water bottle.	Template:Tc	Template:Tc
Template:BlockSprite Minecraft:Mud turning into Minecraft:clay through the use of Minecraft:pointed dripstone.	Template:Tc	Template:Tc
Template:BlockSprite A Minecraft:book being added or removed from a Minecraft:chiseled bookshelf by Minecraft:player, Minecraft:hopper, Minecraft:minecart with hopper, or Minecraft:dropper.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A Minecraft:suspicious sand or Minecraft:suspicious gravel becoming less dusted as the player uses a Minecraft:brush, or more dusted if the player stops using a brush.	Template:Tc	Template:Tc
Template:BlockSprite Template:BlockSprite A suspicious block turning into Minecraft:sand or Minecraft:gravel.	Template:Tc	Template:Tc
All other Minecraft:block/Minecraft:block state changes.	Template:Tc	Template:Tc

Note blocks

The observer can be placed under Minecraft:note blocks to produce bass drum sounds.

Sounds

Template:Edition: Template:Sound table/Block/Stone/JE Template:Edition: Template:Sound table/Block/Metal/BE

Data values

ID

Template:Edition: Template:ID table

Template:Edition: Template:ID table

Block states

Template:El: Template:Bst Template:Bst

Template:El: Template:Bst Template:Bst

History

Trivia

• The current observer texture was created because Minecraft:Jeb kept confusing the front with the back. He said it was inspired by the "rejected texture" created by Tommaso Checchi.<ref name="ReferenceA">Template:Tweet</ref><ref>Template:Tweet</ref>

Gallery

Mojang images

• Rejected graphics for the observer.
  Rejected graphics for the observer.
• Development image of an observer from Jeb.
  Development image of an observer from Jeb.
• The first image released of the new observer texture for Java Edition.
  The first image released of the new observer texture for Java Edition.

See also

• Minecraft:Tutorial:Block update detector
• Minecraft:Redstone Comparator

External links

• Template:Mcnet