Check if twitter username exists - authentication

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The Twitter REST API v1 is no longer active.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>

Answer 3

As API v1 is no longer available, here is another way to check if a twitter account exists. The page headers of a non existing account contain 404 (page not found).
function twitterAccountExists($username){
$headers = get_headers("https://twitter.com/".$username);
if(strpos($headers[0], '404') !== false ) {
return false;
} else {
return true;
}
}

Answer 4

Here is how it works on PHP :
$user_infos = 'http://api.twitter.com/1/users/show.xml?screen_name='.$username;
if (!#fopen($user_infos, 'r'))
{
return false;
}
return true;

Answer 5

This worked for me, close to what sferik has posted.
def twitter_user_exists?(user)
Twitter.user(user)
true
rescue Twitter::Error::NotFound
false
end

Answer 6

You can try to grab the http://twitter.com/username page and read the response to see if you get the "Sorry, that page doesn’t exist!" page.
Edit:
As #Pablo Fernandez mentioned in a comment, it will be better (faster, more reliable) to check the response header, which will be "404 not-found" if the user doesn't exist.

Answer 7

Using Ruby, you could install the twitter gem and then define the following method:
require 'twitter'
def user_exists?(user)
Twitter.user(user)
true
rescue Twitter::NotFound
false
end
Then, simply pass in a Twitter user name or id to your method, like so:
user_exists?("sferik") #=> true
user_exists?(7505382) #=> true

Answer 8

You can try:
<?php
$user = "toneid";
$contents = #file_get_contents('http://www.twitter.com/'.$user);
if (!$contents) {
// Report error
echo "Not a valid user";
} else {
// If is a valid url
echo "OK!";
}
?>

Answer 9

UPDATE: This API is not available since 2012.
According to the api docs you can pass an email address to the user/
show method, I would assume that if a user didn't exist you'd get back
a 404, which should allow you to determine whether or not the user
exists.
eg: http://twitter.com/users/show.xml?email=t...#example.com
result if not exist :
<?xml version="1.0" encoding="UTF-8"?>
<hash>
<request>/users/show.xml?email=tur...#example.com</request>
<error>Not found</error>
</hash