Heads up! This blog post hasn't been updated in over 2 years. CodePen is an ever changing place, so if this post references features, you're probably better off checking the docs. Get in touch with support if you have further questions.

Usernames on CodePen allow uppercase and lowercase. For example, a combination of upper and lower case, like:

http://codepen.io/SaraSoueidan/

You know what was wicked annoying? If you went to, for example:

http://codepen.io/sarasoueidan/

It would fail (404).

Now, it won't. Even if you go to:

http://codepen.io/SarAsOUeiDaN/

You'll get redirected to the correct URL.

HoT DigGiTY doG!