What this tool does
This checker sends the username you enter to Roblox's own public user API. If an account exists with that exact name, it returns the account's user ID and current avatar. If no account matches, the tool tells you so — the name may be free to register, or it may belong to a banned account that Roblox hides from lookup.
Nothing is stored. Each lookup is a live request to Roblox, run when you press Check.
Why the user ID matters
A username can change. A Roblox user ID cannot. If you trade items, report a player, or build a tool that references a Roblox account, the ID is the stable value to use. This checker gives you that ID directly from a username, and links to the account's profile page.
Reading a "not found" result
Roblox's API excludes banned and terminated accounts from search results. A "not found" result here means one of two things: the username has never been registered, or it belonged to an account that Roblox has since banned. This tool cannot tell you which. To confirm a name is free to claim, try registering it on Roblox's own signup page.