Is it ok to make the users email their username?

1. Is it OK to use email address as username?
2. Should I use email or username for login?
3. Is username more secure than email?

Is it OK to use email address as username?

Don't make your e-mail address your user ID

Using your e-mail address to sign into accounts has its benefits. Your ID is unique and easy to remember, and it makes it simple for a service to contact with you when, say, you forget your password. But in some cases, the risks of doing so could outweigh the benefits.

Should I use email or username for login?

Usernames Are Used Across Sites

If your login has an email only field you can benefit as well. Allowing users to log in with a username would help users who forget which email they used to sign up. Users have many email addresses and can't always remember which ones they used for which sites.

Is username more secure than email?

Having a username provides more obscurity than email does which provides security as a bruteforcer would requires the username before being able to perform an attack. An email is not as obscure as a username as email.