Half the "cool" handle lists fail GitHub's sign-up form. Here's what actually works.
Letters, numbers, and single dashes. 39 characters max. No dash at the start or end.
alex_rivera works on X. GitHub rejects it. Use alex-rivera instead.
Birth years, random digits, leetspeak, employer names, and trademarks. Each one gives you a reason to rename later.
Deleted accounts are held for 90 days. The profile 404s, but the sign-up form still says no.
Check your pick on GitHub, npm, X, and the rest in one pass. Then register it the same day.
Six patterns, the full rules, and how DevBio's free generator builds candidates.