A favicon, known in full as a favorite icon, is the small image display that appears on the left of URLs for most of the modern web browsers. The display is a 16×16-pixel image and it may also be displayed next to the name of a site if it is bookmarked. A custom favicon means having your business icon, colors or logo displayed as the image next to your website URL. For websites where no custom favicon is installed, a blank square is displayed next to the URL instead.

Therefore, having a custom favicon for your website design is quite necessary because:

The website appears more credible and professional as a favicon shows attention to detail and leaves the client with the impression of a complete website. Although it is a small addition, it will build a customer’s trust in the professionalism of your website.

A favicon is a way to reinforce your brand. By getting your icon, logo or colors out into an additional web location, your business, band gets better exposure and becomes more recognizable to a customer.

Most importantly, favicons make a site more user-friendly. Most people use tabbed browsers and therefore your custom favicon appears on the tab next to the page title instead of an empty square, thus it is more identifiable and thus better brand reinforcement. Therefore, for a user with multiple open tabs, it is easier for them to return to your website as they can simply recognize your site from the favicon displayed on the tab rather than opening every single tab trying to find it.