{{about|the mechanic in Java Edition that keeps certain chunks loaded all the time|the similar game mechanic in Bedrock Edition|Ticking area}}
{{cleanup}}
{{exclusive|java}}
'''Spawn chunks''' are chunks found around the world [[spawn]] point. They are always loaded, unlike normal chunks, which unload when no players are nearby.

== Usage ==
Normally, old [[chunk]]s beyond the player's chunk loading distance unload. This means the game stops processing those chunks and they are frozen in time. This prevents [[redstone]] mechanisms and farms in unloaded chunks from running in the background. Since spawn chunks remain loaded, events occurring in them continue to process, even if no players are nearby. If the world spawn is set to a laggy area using commands, such as an area with many redstone clocks, lag is present wherever the player is in the world.

== Behavior ==
{{main|Chunk}}
[[File:JE 1.20.5+ Chunk Propagation.png|thumb|Illustration of chunk propagation.]]
The "spawn chunks" behavior arises from a [[chunk#Ticket types|start ticket]] that is created for the [[Spawn#World spawn|world spawn]] chunk. This ticket has a level of 22, which flows (i.e. "propagates") to neighboring chunks. Each time the level flows, it increases its level by 1 until the maximum of 26 is reached. This behavior is illustrated by the picture to the right.

Different levels of propagation have different behaviors. These levels are divided into 4 load types.
{| class="wikitable"
!Load Type
!Level
!Properties
|-
|Entity Ticking
|23 and below
| In the spawn chunks, this consists of a 3×3 chunk area. All game aspects are active. Note that [[Tick#Chunk_tick|chunk ticks]] additionally require a player in range.
|-
|Ticking
|24
|The margin of the 5×5 area. All game aspects are active except that entities are not processed (do not move) and [[Tick#Chunk_tick|chunk ticks]] aren't either.
|-
|Border
|25
| The margin of the 7×7 area. Only some game aspects are active (redstone and command blocks do not work). Mobs still count towards the [[mob cap]].
|-
|Inaccessible
|26 and above
|No game aspects are active, but [[world generation]] still occurs. Mobs no longer count towards the mob cap.
|} 

=== Limitations ===
{{main|Chunk#Limitations}}
There are some limitations which may affect the behavior of spawn chunks.

;Idle timeout
Each [[Dimensions|dimension]] has its own "idle timeout." Without a [[player]] or [[Commands/forceload|forceloaded]] chunks in the overworld, this timeout eventually expires. When the timeout expires, some behaviors such as entity processing stop for spawn chunks and the rest of the dimension. The timeout can be reset by frequently sending entities through a portal.

;Chunk tick
{{see also|Tick}}
Only chunks with horizontal distance between its center and a player less than 128 blocks are ticked on every game tick. This stops events caused by random ticking, such as crop growth.

;Entities
{{see also|Spawn}}
* Hostile mobs more than 128 blocks from a player despawn.
* Passive mobs only spawn inside a 240×240 block area around the player.
* Passive mobs present in the spawn chunks count toward the mob cap. This often prevents friendly mobs from naturally spawning elsewhere in the world.

== Changing location ==
A new world spawn point can be set using {{cmd|setworldspawn}}. If no coordinates are provided, the block position that the player is currently standing on becomes the spawn point. The chunk where the world spawn is located is then given a start ticket with a level of 22 and the ticket for the old spawn chunks is cleared.

== History ==
{{info needed section|when the concept of spawn chunks was introduced}}

{{HistoryTable
|{{HistoryLine|java}}
|{{HistoryLine||?|dev=?|Added spawn chunks.}}
|{{HistoryLine||1.20.5|dev=24w03a|Added [[gamerule]] <code>spawnChunkRadius</code> to control the size of the spawn chunks.|The default spawn chunk propagation is now 3×3 instead of 19×19.}}
|{{HistoryLine|console}}
|{{HistoryLine||xbox=?|xbone=?|ps3=?|psvita=?|ps4=?|wiiu=?|switch=?|Added spawn chunks.}}
}}

== Navigation ==
{{Navbox Java Edition technical|general}}

[[fr:Chunk d'apparition]]
[[ja:スポーンチャンク]]
[[ko:스폰 청크]]
[[pl:Chunk spawnu]]
[[pt:Chunk de renascimento]]
[[ru:Чанк возрождения мира]]
[[uk:Чанк спавну]]
[[zh:出生点区块]]