Username Compatibility Checker
Test a handle against every major platform's rules at once — and see exactly why it gets rejected.
Fits the rules on 5 of 9 platforms as typed. This checks each platform's format rules — not whether the name is already taken.
- Instagram✓ Fits
- Fancy fonts only stick in your Name field and bio, not the @username.
- TikTok✓ Fits
- Style the display name above your @handle — that field takes fonts.
- X (Twitter)✗ Won't work
- These characters aren't allowed: . — use only letters, numbers, underscores.
- Letters, numbers and underscores only — no periods or hyphens.
- Twitch✗ Won't work
- These characters aren't allowed: . — use only letters, numbers, underscores.
- Your display name can only differ from this by letter case.
- YouTube (handle)✓ Fits
- The @handle is separate from your channel name, which can use fonts.
- Reddit✗ Won't work
- These characters aren't allowed: . — use only letters, numbers, underscores and hyphens.
- Permanent — a u/ username can never be changed after signup.
- Snapchat✓ Fits
- Must start with a letter, and can't be changed once set.
- Discord✓ Fits
- Put fonts and symbols in your display name, not the @username.
- Roblox✗ Won't work
- These characters aren't allowed: . — use only letters, numbers, underscores.
- One underscore at most, and never at the start or end.
Fails somewhere? Generate handle-safe alternatives that use only allowed characters, or drop a period/hyphen and keep it 4–15 characters to pass almost everywhere.
Picking one username and grabbing it everywhere sounds simple until a platform rejects it for being too long, using a period, or needing a capital letter. This checker runs your desired handle against nine platforms at once — Instagram, TikTok, X, Twitch, YouTube, Reddit, Snapchat, Discord and Roblox — and tells you exactly which ones will accept it and, when they won't, precisely why.
One thing worth being clear about: this checks each platform's format rules, not availability. A handle can satisfy every rule and still be taken by someone else — you only find that out at the signup form. What this tool saves you is the back-and-forth of discovering, one site at a time, that your name is one character too long or uses a symbol that isn't allowed.
A quick rule of thumb for a handle that works almost everywhere: stick to lowercase letters and numbers, keep it between 4 and 15 characters, skip periods and hyphens, and use at most a single underscore. If your first pick is taken, our handle-safe username generator spins out variations that stay inside those rules. And remember — fancy fonts never save in an @username; those belong in your display name and bio.
Frequently asked questions
Does this check if a username is available?+
No — it checks whether your handle fits each platform's format rules (length, allowed characters, case). A name can pass every rule and still be taken by someone else; you'll only know for sure when you try to register it. This tool tells you which names are even worth trying.
Why does my name pass on Instagram but fail on X?+
Every platform sets its own rules. X (Twitter) limits handles to 4–15 characters and allows only letters, numbers and underscores — no periods or hyphens. Instagram allows periods and runs up to 30 characters. So the same name can be perfectly valid on one and rejected on another.
Why is my fancy or stylish username rejected everywhere?+
The @username field on every platform only accepts plain characters — letters, numbers and a couple of symbols. Fancy Unicode fonts are stripped there. Use styled fonts in your display name or bio instead, which do accept them.
What username works on the most platforms?+
Aim for lowercase letters and numbers, 4–15 characters, no periods or hyphens, and at most one underscore in the middle. A handle that fits that recipe is accepted almost everywhere. If your pick is taken, generate handle-safe variations.
Are these rules up to date?+
They reflect each platform's documented username rules as of 2026 and cover length, character set, case and the main structural quirks. Platforms tweak these occasionally, so treat the result as an accurate guide rather than a guarantee — the final word is always the signup form itself.