Username format checker

Check a stated set of rules

The starting example allows 3–16 English letters, digits and underscores, with an English letter first. These are example settings, not official rules for any game or platform. Change them to match the requirements you want to test.

Spaces, emoji, accented letters and invisible controls fail this tool’s English-letter character rule. Input is checked as entered: it is not trimmed or silently converted. Length is counted in visible characters, which can differ from a platform’s byte or code-unit limit.

Use the result correctly

• A passing result means only that the input meets the settings displayed here. It does not establish availability, approval by a game, or compliance with a publisher’s content filter.
• Set minimum and maximum length from one to sixty-four. If minimum exceeds maximum or either setting is missing, fix the settings before using the result.
• Enable underscores, dots or hyphens separately. This checker does not model reserved words, repeated-punctuation rules or platform-specific restrictions.

No account lookup

All checks run in this browser. The tool does not contact a game or social network and does not send your username to our servers. You do not need to sign in.

Questions

• Does a pass mean the username is available? No. A pass means the text meets your selected format rules. Availability must be checked with the service where you want to use it.
• Are the default settings official platform rules? No. They are a configurable example: 3–16 characters, English letters, digits and underscores, starting with a letter.
• Why does an invisible or accented character fail? The allowed character set is deliberately explicit: English A–Z and a–z, digits, and your enabled punctuation. Other characters fail even when they look similar.