Gamertag and username rules for every major platform

Every platform sets its own rules for what a username can contain, and the limits are the first thing that rejects a name you thought was fine. Below are the current length and character limits for the platforms people ask about most, side by side, plus the common ways a name fails even when it looks valid. Rules shift over time, so treat this as a starting point and confirm the exact spelling in the platform’s own signup or profile flow before you commit.

The limits, side by side

Platform	Length	Allowed characters	Notes
Xbox (gamertag)	up to 12	Letters, numbers, spaces; the system can add a suffix if your name is a duplicate	Spaces are allowed; any suffix is added automatically, not chosen
PlayStation (online ID)	3 to 16	Letters, numbers, hyphens, underscores	No spaces; some older IDs predate these rules
Discord (username)	2 to 32	Lowercase letters, numbers, periods, underscores	Display name is separate and more permissive
Steam (profile name)	up to 32	Broad, including most symbols and spaces	This is your shown name; the account name is separate and permanent
Roblox (username)	3 to 20	Letters, numbers, underscores	No spaces; display name is separate
Minecraft Java	3 to 16	Letters, numbers, underscores	Stored in lowercase; capitalisation is cosmetic

A few of these deserve a closer look because they trip people up.

Xbox lets you use spaces, and may add a suffix

Xbox is one of the few platforms that allows spaces in a gamertag, and it has a duplicate system. If your exact name is already taken, Xbox can append a suffix (often a short number with a hash) so you can still use the display name you wanted. That means two players can show the same name with different suffixes, and the name you read on screen is not always the full unique handle.

PlayStation and Roblox want one solid word

Both PlayStation and Roblox reject spaces in the core username. If your favourite name has a gap, you will need to drop the space, swap in an underscore, or run the words together. Both platforms also keep a separate, more flexible display name, so you can often show a friendlier version while the underlying handle stays compact.

Discord usernames are lowercase by design

The current Discord username system is lowercase only and limits you to letters, numbers, periods, and underscores. Your display name, the one people see in chat, is separate and far more flexible. So a name that looks great as a display name may need to be flattened into lowercase for the actual username.

Minecraft stores names in lowercase

On Java Edition, the system treats your username as lowercase even if you type capitals, so the visible capitalisation is cosmetic. The practical effect: two names that differ only in capitalisation are the same name, and a name is already taken if its lowercase form matches someone else’s.

Steam has two names, and only one is permanent

Steam keeps a permanent account name you cannot change, plus a profile name you can edit freely. Friends see the profile name. When people talk about changing their Steam name, they mean the profile name, which is the flexible one.

Before you commit, check it live

Limits tell you whether a name is even allowed. They do not tell you whether it is free. A name can satisfy every rule above and still be claimed by someone else. The reliable check is always the platform itself: start the signup or profile-edit flow, type the exact spelling, and read the live availability response. For the full method, see how to check if a username is taken.

If you are still choosing, the generator lets you filter by length so the ideas you start from already fit the platform you have in mind.