If your login is an email, should you canonicalize/lower-case it?

Yes, you should accept it as a login but internally lowercase it to rule out matching problems in your database and to ensure you don't have unintended duplicates.

1. Should email logins be case sensitive?
2. Are logins case sensitive?
3. Are emails case sensitive anymore?
4. Should URLs be case insensitive?

Should email logins be case sensitive?

No, email addresses are not case sensitive. Whether you enter an email like this “[email protected]”, like this “[email protected]”, or like this “[email protected]”, it doesn't make an iota of difference.

Are logins case sensitive?

Passwords are case-sensitive to better protect your login information, while usernames are not. This means the system will recognize your username, regardless if there are capital letters or not. Passwords won't be recognize unless it is entered exactly as it was created.

Are emails case sensitive anymore?

So, Are Emails Case Sensitive? No. Email addresses are not case sensitive. If your email address is [email protected] but someone enters it in all lowercase letters, you're still going to receive the email.

Should URLs be case insensitive?

Southern. Google's John Mueller clarifies that URLs are case sensitive, so it matters whether the characters are uppercase or lowercase. Variations in cases can make one URL different from another, similar to how a URL with a trailing slash is different from a URL without the slash.