Roblox Username to User ID
Every Roblox account has a permanent numeric ID that never changes, even when the username does. Enter a username to find it.
Why user IDs matter
A Roblox username can be changed for 1,000 Robux. The user ID cannot be changed by anyone, ever. That makes the ID the only reliable way to identify an account over time.
Developers need it for scripting, moderation, and datastores. Parents need it for a different reason: if someone your child mentions changes their username, the ID is how you tell whether it's the same person as before.
A profile URL contains the ID directly — roblox.com/users/156/profile — so you can also read it straight off the address bar.
Checking one account is a snapshot. RoGuard watches continuously.
RoGuard tracks your child's Roblox account around the clock — every game they play, every new friend, every bio change — and emails you when something looks wrong.