User URLs based on the usernames Is there a module that changes the user URL from "user/1" to "user/username"?
Pathauto does exactly that.

All new user aliases generated after enabling the module will look like users/[user:name] (obviously this could be changed in module configuration - Configuration / URL aliases / Patterns).

You can use "Bulk update" to generate aliases for already existing users (and other type of content).