Check if twitter username exists

Question

Is there a way to check if a twitter username exists? Without being authenticated with OAuth or the twitter basic authentication?

Answer 1

UPDATE 2021: This API is not available.

As of right now, you're better off using the API the signup form uses to check username availability in realtime. Requests are of the format:

https://twitter.com/users/username_available?username=whatever

And give you a JSON response with a valid key giving you a true if the username can be registered:

{"valid":false,"reason":"taken","msg":"Username has already been taken","desc":"That username has been taken. Please choose another."}
{"valid":true,"reason":"available","msg":"Available!","desc":"Available!"}
{"valid":false,"reason":"is_banned_word","msg":"Username is unavailable","desc":"The username \"root\" is unavailable. Sorry!"}

The reason this is better than checking for 404 responses is that sometimes words are reserved (like 'root' above), or a username is actually taken but for some reason the account is gone from the Twitter front end.

Answer 2

UPDATE

The Twitter REST API v1 is no longer active.

So use https://api.twitter.com/1.1/users/show.json?screen_name=username

---

You can also use the API with username :

http://api.twitter.com/1/users/show.xml?screen_name=tarnfeld

Will give you :

<?xml version="1.0" encoding="UTF-8"?>
<user>
  ...................
  <screen_name>tarnfeld</screen_name>
  <location>Portsmouth, UK</location>
  .................
  </status>
</user>

Or if not exist :

<?xml version="1.0" encoding="UTF-8"?>
<hash>
  <request>/1/users/show.xml?screen_name=tarnfeldezf</request>
  <error>Not found</error>
</hash>