What is a favicon?
A favicon is the small icon a browser shows next to a page title in the tab bar, the address bar, the bookmarks list, and the history menu. Mobile operating systems also use it when a visitor saves the site to their home screen. The image is tiny on the screen, often as small as 16 pixels per side, but it carries a surprising amount of weight: it is one of the first things a returning visitor recognizes, and a missing favicon makes a site look unfinished.
Modern browsers ask for several sizes of the same icon. The single favicon.ico file from a decade ago still works, but for crisp results on retina laptops, high-resolution Android phones, and bookmarked iPhone shortcuts you also need PNG files at a handful of larger sizes. This generator outputs every size browsers look for and writes the matching web manifest, so you can install everything by dropping one folder into your site.