How it works
16×16 and 32×32 px appear in browser tabs; 48×48 is used on some Windows tiles and bookmarks.
PNG to ICO bundles those three sizes into one favicon.ico file for simple hosting.
Frequently asked questions
How do I add the favicon to my site?+
Upload favicon.ico to your site root. Optionally add <link rel="icon" type="image/png" sizes="32x32" href="/favicon-32x32.png"> for modern browsers.
Why convert PNG to ICO?+
Some hosts and tools only look for favicon.ico. ICO stores multiple resolutions in one file so tabs stay sharp on retina displays.