Regex for Username (3-16, alnum/underscore)
Matches a username of 3-16 letters, digits or underscores.
^[a-zA-Z0-9_]{3,16}$
Proof it works
| Sample | Should match | Result |
|---|---|---|
john_doe |
yes | pass |
user123 |
yes | pass |
ab |
no | pass |
this_name_is_way_too_long |
no | pass |
bad name |
no | pass |