Roblox username rules in 2026

Roblox's account naming system has three independent rules sets. Mixing them up is why so many "available" usernames get flagged after signup. The breakdown below reflects the current 2026 policy.

Username (the @ handle)

Length: 3 to 20 characters.
Allowed characters: letters A–Z / a–z, digits 0–9, and a single underscore _. No more than one underscore in the entire name.
Case: the handle is case-insensitive for sign-in but the original case is preserved for display.
Change cost: 1,000 Robux per change. The previous handle becomes available to others after a cooldown.
Forbidden: any string the moderation classifier flags — including reasonable-looking words that share substrings with slurs in other languages. There is no published list; you find out at signup.

Display name (the @-less name shown in chat)

Length: 3 to 20 characters.
Allowed characters: any printable Unicode, including emoji and Cyrillic. The script-mixing check (added 2024) blocks names that combine scripts in suspicious ways — pure Latin + emoji is fine; Latin + Cyrillic that spell the same word is not.
Change cost: free, once every 7 days.
Lookalike check: display names that visually resemble Roblox staff handles or famous creators are rejected at submission.

Group name (covered in the group name generator)

Length: 3 to 50 characters.
Allowed characters: letters, digits, spaces, and a small punctuation set (-, _, ., ').
Uniqueness: group names are globally unique. Once taken, they're locked even if the group is empty or banned.

The traps that get accounts flagged after signup

The classifier runs on three signals after the name is created: substring matching against an evolving slur list, n-gram similarity to known leetspeak slurs, and report frequency from other players. A name that passes signup can still get force-renamed weeks later if reports stack up.

The fixes are unglamorous:

Avoid leetspeak substitutions of letters in common slurs (you don't know what list is current).
Avoid number-suffixed dictionary words that are also gamertags for banned players.
Avoid mixed-script display names unless the mix is obviously stylistic (e.g. ★ decorations).

Generators that respect the rules

The Bloxyblox username generator checks the live Roblox availability endpoint before showing a name, so anything it surfaces is signable at that moment. The classifier-based bans above can still hit afterwards — no public tool can predict them.