How do I downgrade Minecraft to play on a server running an older version?

Question

How do I downgrade Minecraft to play on a server running an older version?

Answer 1

Caution - Notch doesn't want you to do this!

You'll need to source the files for the previous version yourself and place them in .minecraft/bin, and tell your firewall to prevent Minecraft from accessing the internet so it can't download the new files. Try and find a friend who hasn't downloaded the update yet :-)

Answer 2

The answer varies depending on what launcher version you are using. In the latest (when this post was written), you can choose whether or not you wish to update. If so, you press Update, and if not, you press Not Now.

If you are using an older launcher version, you would have to get the old minecraft.jar and put it in your .minecraft\bin, wherever that may be. Don't forget to either kill your internet when logging in and play offline, or use your firewall to prevent Minecraft from accessing the internet.

The minecraft.jar s can be downloaded from the link below, just change it to whatever version you would like to download. The link below will give you version 1.4.6. If you want a snapshot version, use the second link below. As you can see, that one will give you version 12w50b. Note that as fredley said, Notch disproves of this.

http://assets.minecraft.net/1_4_6/minecraft.jar
http://assets.minecraft.net/12w50b/minecraft.jar