Facebook API error 191

UPDATE:
To answer the API Error Code: 191
The redirect_uri should be equal (or relative) to the Site URL.

Tip: Use base URLs instead of full URLs pointing to specific pages.

NOT RECOMMENDED: For example, if you use www.mydomain.com/fb/test.html as your Site URL and having www.mydomain.com/fb/secondPage.html as redirect_uri this will give you the 191 error.

RECOMMENDED: So instead have your Site URL set to a base URL like: www.mydomain.com/ OR www.mydomain.com/fb/.

I went through the Facebook Python sample application today, and I was shocked it was stating clearly that you can use http://localhost:8080/ as Site URL if you are developing locally:

Configure the Site URL, and point it to your Web Server. If you're developing locally, you can use http://localhost:8080/

While I was sure you can't do that, based on my own experience (very old test though) it seems that you actually CAN test your Facebook application locally!

So I picked up an old application of mine and edited its name, Site URL and Canvas URL: Site URL: http://localhost:80/fblocal/

I downloaded the latest Facebook PHP-SDK and threw it in my xampp/htdocs/fblocal/ folder.

But I got the same error as yours! I noticed that XAMPP is doing an automatic redirection to http://localhost/fblocal/ so I changed the setting to simply http://localhost/fblocal/ and the error was gone BUT I had to remove the application (from privacy settings) and re-install my application and here are the results:

After that, asked for the publish_stream permission, and I was able to publish to my profile (using the PHP-SDK):

$user = $facebook->getUser();
if ($user) {
try {
$post = $facebook->api('/me/feed', 'post', array('message'=>'Hello World, from localhost!'));
} catch (FacebookApiException $e) {
error_log($e);
$user = null;
}
}

Results:

This is just because of a URL mistake.

Whatever website URL is specified should be correct.

I mentioned website URL as http://localhost:3000/ and domain as localhost, but in my browser I was running http://0.0.0.0:3000/.

When I ran server as localhost:3000 it solved the problem.

As I mentioned, the site URL as localhost Facebook will redirect to the same, if we are running 0.0.0.0:3000, it will rise error that "Given URL is not allowed by the Application configuration".

I was also facing the same problem when I am using the facebook authentication method. But I rectify that issue with following changes in Facebook api (Apps >> My App >> Basic).

1. I removed the url which i have given in ===> App on Facebook (Canvas URLs)
2. I gave site url only in ===> Website with Facebook Login option

Then i gave that AppId and App Secret in my webpage.

So by clicking on login button, It ask for access permissions then it redirect it to give url (Website with Facebook Login ).

Had the same problem:

$params = array('redirect_uri' => 'facebook.com/pages/foobar-dev');
$facebook->getLoginUrl($params);

When I changed the redirect_uri from the devloper page to the live page, 191 Error came up.

So I deleted the $params:

$facebook->getLoginUrl();

After the app-request now FB redirects to the app url itself f.e.: my.domain.com

What I do now is checking in index.php of my app if I'm inside FB iframe or not. If not I redirect to the live FB page f.e.:

$app = 'facebook.com/pages/foobar-live';
$rd = (isset($_SERVER['HTTP_REFERER'])) ? parse_url($_SERVER['HTTP_REFERER'], PHP_URL_HOST) : false;
if ($rd == 'apps.facebook.com' || (!isset($_REQUEST['signed_request'])))  {
echo '<script>window.parent.location = "'.$app.'";</script>';
die();
}

I have noticed also that even if you specify your website under secion - Website With Facebook Login -> Site url as e.g. http://example.com, but if your App Domains section is empty, and you open website as www.example.com you will get this error, too. To avoid it in "App Domains" section write example.com, that will allow subdomains, like www.example.com, something.example.com etc

For me, it was a missing app domain. Go into the app, and make sure that you have the root of your site set up as an app domain. See screenshot.

in the facebook App Page, goto the basic tab. find "Website with Facebook Login" Option.

you will find Site URL: input there put the full URL ( for example http://Mywebsite.com/MyLogin.aspx ). this is the URL you can use with the call like If the APP ID is 123456789

https://graph.facebook.com/oauth/authorize?client_id=123456789&redirect_uri=http://Mywebsite/MyLogin.aspx&scope=publish_actions

Something I'd like to add, since this is error 191 first question on google:

When redirecting to facebook instead of your own site for a signed request, you might experience this error if the user has secure browsing on and your app does redirect to facebook without SSL.

Working locally... I couldn't get the feeds api to work, but the share api worked pretty much straight away with no problems.

I fixed this by passing the redirect url to the FacebookRedirectLoginHelper::getAccessToken() in my callback function:

Changing from

try {
$accessToken = $helper->getAccessToken();
}
...

to

try {
$accessToken = $helper->getAccessToken($fbRedirectUrl);
}
...

I am developing on a vagrant box, and it seems FacebookRedirectLoginHelper::getCurrentUrl() had issues generating a valid url.

For me it's the Valid OAuth Redirect URIs in Facebook Login Settings. The 191 error is gone once I updated the correct redirect URI.