Add the following code to your site's tags
A favicon (short for favorite icon), also known as a shortcut icon, website icon, tab icon, URL icon, or bookmark icon, is a file containing one or more small icons, associated with a particular website or web page. A web designer can create such an icon and upload it to a website (or web page) by several means, and graphical web browsers will then make use of it.
.png and .ico format, simple and fast online favicon generator tool. Create .png and .ico icons in 14 different image sizes.