Usernames that follow the rules
Many sites and games have username rules: a minimum and maximum length, at least one number, sometimes a symbol or a capital letter. Set those here and every result is guaranteed to follow them, so you can stop guessing and retyping.
Why an underscore
When you require a symbol, the generator uses an underscore because it's the one symbol allowed almost everywhere, including X, Twitch, Instagram and TikTok.
Each result lists the platforms whose length and character rules it meets. Rules change from time to time, and availability can only be checked on each site.