WhatsApp Username Checker

Every rule this checker enforces

WhatsApp accepts a username only when it passes all of these checks. The checker above runs the same list, live. Rules last verified against the app on July 4, 2026.

Rule	What it means
3 to 30 characters	Usernames must be 3 to 30 characters long. Trim it down or add a little more.
Lowercase only	Uppercase letters are not accepted. Use the lowercase version.
Only letters, numbers, . and _	Spaces, emoji, accents, and other symbols are not allowed. Replace spaces with a period or underscore.
At least one letter	A username cannot be numbers and symbols only. Add a word.
No web-address prefix	Names starting with "www." are blocked because they look like links. Drop the prefix.
No period at the start or end	Begin and end with a letter or number, not a period.
No consecutive periods	Two periods in a row are rejected. Use a single period.

Examples that pass and fail

Username	Result	Why
anna.perez	Passes	Lowercase letters with a single period
tapas_designs	Passes	Letters and one underscore
leo99	Passes	Letters with numbers
Anna Perez	Fails	Uppercase letters and a space
www.mycafe	Fails	Starts like a web address
12345	Fails	No letters
.quiet.mind	Fails	Starts with a period
sam..reads	Fails	Consecutive periods

Why a valid-looking name can still be rejected

Format is only half the story. A name that passes every rule here can still fail in the app because it is already taken, reserved, too close to a brand, or because usernames have not reached your account yet. WhatsApp rolls the feature out in waves, between 3 and 30 characters is the size of the playing field, but availability is decided inside the app alone.

The full background, including how to set a username once the option appears for you, is in the username rules guide. If you are still deciding on a name, read what actually changes with usernames first, and when your first idea fails, the username generator builds valid alternatives from it.