Check whether a Gravatar exists for a specific e-mail

Gravatar is a great tool for getting avatars and profile images associated with a specific e-mailaddress. By default, if somebody has specified an image for their e-mail, that image can easily be retrieved. If the user doesn't have an e-mail, Gravatar will return a standard image.

But what if you don't want that default image? Gravatar has no easy option to check whether an image exists. WordPress has a function for this, called has_avatar(), but that function is not much of a use, because it also returns true when Gravatar gives you the standard image.

Fortunately, there's a smart way in PHP to check if a Gravatar exists for a specific e-mailaddress. The method could come in very handy if you're in WordPress and want to output comments in a custom format.

Anyway, let's get started!

Function to validate an e-mail

To check whether a Gravatar exists, we'll write a function that can be reused. The function is called validate_gravatar($email) and it takes the e-mailaddress needed to validate as a parameter.

The function sends a request to the Gravatar database. If the request returns a custom avatar, the $has_valid_avatar will be set to true. If not, the $has_valid_avatar will be set to false.

Finally, the function returns the value of the $has_valid_avatar variable. This means that the function output will always be a simple boolean.

function validate_gravatar($email) {
    // Craft a potential url and test its headers
    $hash = md5(strtolower(trim($email)));
 
    $uri = 'http://www.gravatar.com/avatar/' . $hash . '?d=404';
    $headers = @get_headers($uri);
 
    if (!preg_match("|200|", $headers[0])) {
        $has_valid_avatar = false;
    } else {
        $has_valid_avatar = true;
    }
 
    return $has_valid_avatar;
}

You should place the above function in the file you need to use it in. So if you're using it in functions.php, place it there.

Using the validate Gravatar e-mail with the WordPress comments - example

Now that we have a handy function to check if a Gravatar exists, how do we use it? I like to define the following three variables when I want to use this in WordPress when I'm creating a custom WordPress comments walker.

First, we'll get the email of the comment author. Then, we'll check whether that person has his own Gravatar. Now you can use the $rjs_has_gravatar variable with a simple php if-statement. Last, we'll get the avatar and store it in a variable.

$rjs_comment_email = get_comment_author_email();
$rjs_has_gravatar = validate_gravatar($rjs_comment_email);
$rjs_gravatar = get_avatar( $rjs_comment_email, 160 );

Note: the third step is optional. I like to do it like this, because it makes the code more clear.

If you've declared those three variables, you could use them like this to display the avatar <img> tag. The get_avatar() function gets that tag (function in Codex).

<?php if ($rjs_has_gravatar) { echo $rjs_gravatar; } ?>

You could also use it to show or hide the <img> tag plus a container.

<?php if (get_option('show_avatars', true) && $rjs_has_gravatar) : ?>
 
<div class="rjs-comment-authorimage"> <!-- Container -->
    <?php if ($rjs_gravatar) { echo $rjs_gravatar; } ?> <!-- <img> tag -->
</div> <!-- Container closing tags -->
 
<?php endif; ?>

Conclusion

As you see, it's very easy to check with PHP and/or WordPress whether there exists a Gravatar. The technique can be used both on WordPress and non-WordPress situations, so it's very versatile. If you're using this code in a non-WordPress situation, make sure to check whether the functions used in the examples are available.

Published by Ralph J. Smit on 29 January 2021 in Guides. Last updated on 11 March 2022.