Recover a minecraft seed

The world I've been playing crashed recently and took the level.dat with it, so I've recreated it, however I have no idea what my seed used to be, and I really don't want to end up with another corrupted game world from exploring with the wrong seed.

How can I recover the seed which was used to generate my world?

Solution 1:

This can be done using a third party tool, NBTExplorer which reads the data files used by Minecraft:

1. Open the save folder for the world, e.g. .minecraft\saves\MyWorld

2. Find the file called level.dat_mcr and copy it out of the save folder

3. Rename the file to level.dat

4. Open it with NBTExplorer

5. Expand the 'Data' tab by clicking on the [+] button next to it.

6. Double click on the RandomSeed key, and you'll get a popup window containing the original seed for the level, like this:

   

7. Copy this value into the same place in the new level.dat for your save file, then save and close it.

Your new level.dat file will then have the same seed as the old one.