Use an emoji as a favicon

An emoji can be a favicon with no separate image file. Put the character inside a small inline SVG and use that SVG as a data URL:

<link rel="icon" href="data:image/svg+xml,<svg xmlns=%22http://www.w3.org/2000/svg%22 viewBox=%220 0 100 100%22><text y=%22.9em%22 font-size=%2290%22>😉</text></svg>">

At the time this was written, the technique worked in Firefox and Chrome. Safari handled SVG favicons through its monochrome mask-icon format, so it did not display this version.

The result also depends on the operating system’s emoji font, which means the same favicon can look slightly different across devices. For a playful personal site, that is usually part of the appeal.