Minecraft: How to change your existing world’s random seed

Sometimes you may want to change the random seed of an existing level in Minecraft. Sometimes (Like in my case), the file somehow gets corrupted and the seed is ‘forgotten’ by Minecraft, or maybe you just want to generate new chunks with a new seed.

Changing the world seed is surprisingly easy. Here’s a short step-by-step guide on how to do it:

WARNING: This may erase your inventory on singleplayer. It is recommended that you put your inventory into a chest before doing this.

Long version:

1. Create a new world in Minecraft with the seed you want. Name it whatever (In this guide, it is called “NewWorld”. (You’ll see where I’m going with this.)

2. Once the world is created, save it and close minecraft.

3. Press Windows key + R (Or go to Start->Run), type in %APPDATA% and press Enter. (If you’re on Linux or Mac just find the .minecraft folder and skip to step 5)

4. Go to the .minecraft folder in the window that pops up.

5. Now, go to the “saves” folder. In this folder, go to the NewWorld folder (Or whatever you named the world).

6. Select level.dat and press Ctrl-C

7. Go back to the saves folder. Assuming you want to change the seed of “OtherWorld”, go to the “OtherWorld” folder.

8. Overwrite the level.dat in the folder with the one you just copied.

9. “OtherWorld” will now have the seed that you used for “NewWorld”

Short version:


Make a new world with the seed you want, copy the level.dat from that world to your other world (The one you want to change the seed of). The other world will now use the seed you used for the new world.

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I hope this helps someone. I needed to do this for my server today, and it worked well for me.