Minecraft:World seed

Template:For The world seed (or simply seed; referred to as seed for the world generator in-game) is a value made up of character(s) (including negative or positive integers) that is used as the basis for generating every Minecraft world.<ref>A Short Demystification of the 'Map Seed' - Jens Bergensten on Mojang.com; February 23, 2011</ref>

Compatibility

Seeds are somewhat compatible between Java and Minecraft:Bedrock Edition, with terrain generation and biomes being the same. However, the placement of generated Minecraft:structures differs between these editions.

World generation

Whenever the game has to generate a new world, it calls upon an algorithm known as Template:W. This algorithm outputs a pseudo-random value that is then used to determine the characteristics and features of the world. However, the algorithm always outputs the same value each time for a constant starting point (seed). Thus, the same seed generates the same terrain every time.

A world's seed is set when that world is created. By default, it is decided automatically, but it can also be set manually. Setting and reusing a seed from one world generates the same world. Either a number or a word/phrase can be used, including negatives. If a word/phrase is used, it is converted into a 32-bit integer using the .hashCode() method.

Whenever the world generation algorithm is updated (usually by adding new biomes to the game), the same seed no longer generates the same terrain. If the seed or generator changes in a saved world, new Minecraft:chunks are based on the new seed and no longer match those from the old seed. Deleted chunks can regenerate if the seed and generator remain the same, but changes if either the seed or generator changes. In fact, deleting chunks is sometimes done to let newly-introduced features appear in an old world; see Minecraft:Tutorials/Updating old oceans in 1.13 using MCEdit.

Because seeds are simply random values read into an algorithm and not actually names of different worlds, using a certain seed does not result in a world with any relevance to the value of that seed. For instance, using a Minecraft:biome name as the seed does not necessarily result in the creation of a world with primarily that biome, nor does it spawn the player within the said biome.

Determining the seed

Template:IN, the player can enter the Minecraft:command Template:Command to view and copy the world's seed. This command is available in singleplayer worlds even if cheats are off. The player can also select 'Re-create' in the Worlds menu to see the seed.

Template:IN, the seed can be found and copied on the world options screen. There are also Minecraft:seed templates that offers the player several pre-set seeds to generate worlds with specific features near the spawn point. Additionally, the beta version has a visible seed on the top of the screen.

Changing the seed

Template:Exclusive The seed of a world can be changed at any time using world templates. By exporting a world and unzipping the file, one can place a Minecraft:manifest.json file in the world's folder with the world_template type, and allow_random_seed:true. When zipped into a .mctemplate file, it can be imported into the game. It appears under the Template:UI list of world templates, which, when selected opens the Create new world screen with the option to change the seed. However, this will not create a new world – all saved chunks are still in the world, meaning that only the world seed is changed; even Minecraft:achievements can still be earned. This also allows various other world creation options to be changed, such as flat world, bonus chest, Hardcore, and starting map, clear all player data, or even lock the world in older versions.

Notable seeds

Template:Info needed section The following map seeds have, at one point or another, been used for generating official Minecraft maps and resources or otherwise significant community material.

• The Java Edition demo world seed can be played in the full version by entering Template:Cd in the seed input.
  • The Beta 1.3_01 PC Gamer demo world seed can be played in the appropriate era by entering Template:Cd, all lowercase unlike the famous seed where the G is capitalized, in the seed input.
• The seeds for many of the Minecraft:panoramas used on the title screen are as follows:
  • The panorama used between Beta 1.8 Pre-release and 18w22c is either Template:Cd or Template:Cd,<ref>Template:Reddit</ref> generated between Beta 1.6.6 and Beta 1.7.
  • Bedrock Edition 1.2.0 uses Template:Cd, which is the same seed as the "Winding River" Minecraft:seed template generated before 1.18.0.
  • Java Edition 1.13 uses Template:Cd, which is the seed resulting from typing Template:Cd in as a seed, generated in snapshot Minecraft:18w22a.
  • Java Edition 1.14 uses Template:Cd, taken in Minecraft:18w48a.
  • Java Edition 1.15 uses Template:Cd, taken in Minecraft:19w40a.
  • Java Edition 1.16 uses Template:Cd, taken in Minecraft:20w13a.
  • Java Edition 1.18 uses Template:Cd, taken in Minecraft:21w40a.
  • Java Edition 1.19 uses Template:Cd, which is the seed resulting from typing Template:Cd in as a seed, taken in Minecraft:22w15a.
  • Java Edition 1.20 uses Template:Cd, taken in Minecraft:23w14a.
  • Java Edition 1.21.6 and Bedrock Edition 1.21.90 use Template:Cd, taken in Minecraft:25w20a and Preview 1.21.90.26, respectively.
• The seed for the original pack.png file is Template:Cd, taken some time before the release of Alpha v1.2.2<ref>Template:Reddit</ref>. It generates most correctly from Alpha v1.2.0 to Alpha v1.2.5, but can also be generated up to Beta 1.7.3 with minor population differences. It's also the default seed for Bedrock Edition's New UI of Create New World when no seed is entered or created since Minecraft:Bedrock Edition beta 1.18.20.21. This seed spawns the player in a Minecraft:savanna biome at coordinates Template:Cd.
• The seed for the Skull on Fire Minecraft:painting is either Template:Cd or Template:Cd, generated in Alpha v1.1.2_01 or prior.<ref>Template:Reddit</ref>
• The seed used for the original Minecraft:Herobrine hoax screenshot is Template:Cd, generated in Minecraft:Alpha v1.0.16_02.
• The seed used for the original Minecraft:Herobrine hoax livestream is Template:Cd, generated in Minecraft:Alpha v1.0.17_04.
• Seeds used for the Minecraft:Legacy Console Edition tutorial worlds:
  • Each world is referred to by its respective Minecraft:Xbox 360 Edition update.
  • TU1 and TU3 used the seed Template:Cd
  • TU5 used the seed Template:Cd
  • TU7 and TU9 used the seed Template:Cd
  • TU12 and TU14 used the seed Template:Cd
  • TU19, TU31, TU46, and TU69 were artificially-created and can't be generated by any seed.

Generation anomalies

Some seeds are known to cause strange effects in the world generation, due to their mathematical properties. See Minecraft:Anomalous world seeds for more information.

Technical

Realms

Template:IN, a player can type Template:Cmd in the chat. Template:IN, the seed is not visible when playing on Realms, but can be seen by downloading the world.

General

If the seed contains characters other than digits (except the first character, which can be "-" or "+") or falls out of range of a Java Template:Cd number (an integer between −2⁶³ and 2⁶³−1), the Java String.hashCode() function is used to generate the seed number. This restricts Minecraft to a subset of the possible worlds to 2³² (or 4,294,967,296), due to the Template:Cd datatype being used. A numeric seed or a random (blank) world seed must be used to access the full set of possible worlds (which is 2⁶⁴, or 18,446,744,073,709,551,616, or 18.4 quintillion).

Overlap between editions

All Java and Bedrock Edition seeds in the range from -9,223,372,036,854,775,808 to 9,223,372,036,854,775,807Template:Verify (64-bit seeds) generate the same terrain and Minecraft:biomes in both Java and Bedrock Edition. However, Minecraft:structures, Minecraft:features (i.e. decorators), Minecraft:carver caves, and mob spawns will generate differently.

History

External links

Bedrock and Java Editions

• Chunkbase Minecraft Apps: Online seed/map explorer tool
• Minecraft Seeds on Reddit: Community-driven Minecraft Seeds
• Minecraft Seeds: Community-driven Minecraft Seeds
• LookingForSeed: Find Minecraft seeds from various categories

Java Edition only

• Random Seed Reader: Local Java tool
• Minecraft SeedHunt: Selected Seeds from various categories for Java 1.16
• Minecraft Seeds Java Edition: New Seeds for 1.16.4 Version
• SeedCracker: guess a seed from a multiplayer server
• Seeder: Seed/map explorer tool and finder for Java