What is the format of Minecraft.net account names?

The information I have a use for is:

  • what characters are permitted or prohibited?
  • what is the maximum length?
  • are they always treated as case-insensitive?

However, a complete, exact definition of the allowed format would be appreciated.


2 Answers 2


The username must be between 3 and 16 characters (inclusive).

The characters permitted are :


Usernames are case-sensitive in games (above your head), but when logging in using the username, whether is it in caps or not, will still work.

  • 5
    Additional info: Logging in with a different username case does not change how you appear in-game.
    – Kevin Reid
    May 8, 2011 at 20:02
  • 3
    The way Minecraft treats usernames is called case-preserving (though that term is usually only used when discussing filesystems).
    – Ben Blank
    May 8, 2011 at 23:08
  • Are spaces allowed?
    – spudwaffle
    Jan 2, 2013 at 17:29
  • @spudwaffle No. May 7, 2013 at 14:42
  • Can the name start with a number? Dec 7, 2013 at 3:18

Trying to register with an illegal character gives an error and mentions the following as allowed:


And the longest username I could register was 'thisisalongusern'


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .