Username Format Validator

Instantly see which platforms accept your handle and which reject it — with a clear reason for every failure.

Why format rules vary

Every platform has its own rules for what characters are allowed, where dots can appear, whether consecutive underscores are permitted, and how capitalization is treated. A handle that works on Threads may fail on Twitch, and vice versa.

Pattern that works everywhere

Lowercase letters and numbers only, with an occasional underscore or period in the middle (not at the start or end), is the safest pattern for cross-platform consistency. Avoid hyphens entirely — most platforms reject them in usernames.

The safest cross-platform pattern

If you want one handle that passes every platform’s format rules:

  • Lowercase letters and numbers only, 3–15 characters
  • Optional separator in the middle: a single underscore or period (never at the start or end)
  • Avoid hyphens — Instagram, TikTok, X, and Snapchat reject them
  • Avoid consecutive punctuation — no double dots or double underscores

A handle following this pattern will pass format validation on all 16 platforms NameSniper checks.

Frequently Asked Questions

Can I use dots in an Instagram username?

Yes — periods are allowed in Instagram usernames, but two consecutive periods are not, and a username cannot start or end with a period.

Can I use special characters on TikTok?

TikTok usernames allow letters, numbers, underscores, and periods. Hyphens, spaces, and other special characters are not allowed.

Does this check username availability?

No. This tool only tests format validity (characters, length, platform rules). To check if a username is actually available on each platform, use the full NameSniper checker.

Can I use emoji in usernames?

No major platform allows emoji in usernames themselves. Some allow emoji in display names or bios — see the Social Media Character Limits tool for specifics.

Why does Bluesky accept my handle without a domain?

Bluesky uses DNS-style handles that look like alice.bsky.social. When you type just the short part (like alice), Bluesky auto-appends .bsky.social during signup. The validator accepts both forms so you can check availability either way.

Can I use capital letters in usernames?

Most platforms treat usernames as case-insensitive — BrandName and brandname resolve to the same account. The exception is npm, which rejects uppercase entirely (NPM is invalid, not an alias for npm). For consistency, lowercase everywhere is the safest choice.

Why are hyphens rejected on most platforms?

Hyphens are rejected on most platforms as a product decision — the exact reason has never been publicly documented by the platforms themselves. GitHub and LinkedIn allow hyphens; Instagram, TikTok, X, and most others do not. Underscores and periods are the broadly-safe separators if you need word boundaries in a handle.

Can I use international or non-Latin characters?

No major platform allows non-ASCII letters in usernames. YouTube is a partial exception — CJK characters (Chinese, Japanese, Korean) are accepted in handles. For a consistent cross-platform identity, stick to lowercase Latin letters, numbers, and a minimal set of separators (. or _).

Does this check reserved words or trademarks?

Format rules only. Reserved words (like "admin" on Twitter/X) are noted in the validator output but platforms also enforce their own policies. For trademark conflicts, use NameSniper's full checker — it cross-references USPTO records for registered trademarks in relevant business classes.

Check All Platforms at Once

Don't check one platform at a time. NameSniper checks domains, social media, and trademarks in a single search.