Roblox username rules at a glance
Roblox usernames support letters and numbers only — no underscores, hyphens or other symbols. The name must start with a letter, not a number, and can be between 3 and 20 characters long. Roblox usernames are unique across the platform and are permanent once set (you can display a separate display name, but your username cannot be changed).
Because Roblox usernames are permanent, it's especially worth taking your time finding something you'll be happy with long-term. A name that felt clever at 12 might not feel the same at 18. Think about how it'll look on your profile in a few years, not just right now.
Tips for a great Roblox username
Your Roblox username is permanent. Unlike most platforms, you cannot change your Roblox username after account creation. Choose carefully — generate a solid shortlist and sit on it before deciding.
Numbers at the end are fine, strings are not. "Blaze7" looks intentional. "Blaze738492" looks like a taken-name workaround. Keep trailing numbers short and meaningful.
Avoid anything embarrassing long-term. Roblox has a large younger player base, but many users grow up on the platform. A name that's funny now may not be in five years.
Use the display name feature. Roblox lets you set a separate display name that can be changed. Your username is your permanent identifier, but your display name is what most people see day to day.
Frequently asked questions
Can I change my Roblox username?
No. Roblox usernames are permanent and cannot be changed after account creation. You can set a display name (which is shown to other players in-game) and change that periodically, but your underlying username is fixed.
Can I use underscores in a Roblox username?
No. Roblox usernames only support letters (A–Z) and numbers (0–9). Underscores, hyphens and all other special characters are not permitted.
Does my Roblox username have to be unique?
Yes. All Roblox usernames are unique across the platform. If your chosen name is taken, you will need to try a variation. Check availability at account creation — once someone has a name, it stays theirs permanently.
What is the difference between a Roblox username and display name?
Your username is your permanent account identifier — it appears in your profile URL and cannot be changed. Your display name is shown to other players in-game and in friend lists, and can be updated periodically. The generator creates ideas suitable for use as either.