Worlds generated prior to 1.3.4 will never have a viewable seed while they were generated with a random seed, that information was only used during world creation, and was not stored in the world file. In 1.3.4, an experimental feature setting was added to allow players to see, copy, and input the world seed. Worlds generated in 1.3.4 or later will always have a world seed. The World Seed feature enables the display of the random seed used to generate a Terraria world, and allows the player to input a custom seed manually when creating a new world.

For seeds that can be planted, see Seeds. For the ammunition fired from a Blowpipe, see Seed.