favicon-imagesThe images that you see next to blog comments here are not the regular gravatar pictures, instead they are favicons pulled from the website of the person who has written that comment.

Same is the case with favicons that are displayed near external hyperlinks in the tech river. With these images, you can easily figure out the target page without having to look at the browser’s status bar.

tech-river 

Google Shared Stuff (S2) offers a secret URL that can automatically pull favicon images of any website provided you know the URL. The images are in the PNG format (not ICO) and hence will render correctly in all browsers via the <img> tag.

The syntax for favicons is google.com/s2/favicons?domain=<www.abc.com>

For instance, if the site address is labnol.org, the URL of favicon image labnol favicon will be:

http://www.google.com/s2/favicons?domain=www.labnol.org

To see all this in action, go to your Google Profile page and check the URL of favicon image that is displayed next to your website link – see example.

Now that you know the basics, try this WordPress plugin I wrote to make it easier for you to integrate favicons in your blog comments. Here’s the internal code:

if (!empty($comment->comment_author_url)) {
$url = preg_replace('/^http:\/\//', '', $comment->comment_author_url);
if ($url != "") {
$imgurl = "http://www.google.com/s2/favicons?domain=" . $url;
echo '<img src="' . $imgurl . '" width="16" height="16" />';
}
}

This gets slightly complex if you are on the Classic Template of old blogger since the authorURL is not directly available and you may require some JavaScript manipulation to get the URL from <$BlogCommentAuthor$>.

However in the new version of Blogger, you can get the URL of the commenter directly using the authorUrl Data Tag so the above technique can be ported to the new Blogger.

And if you have not added a favicon to your blog yet, check this guide on how to add favicons.

Thanks Nick, Simon and Jason.