ICO vs PNG for Favicons
ICO is universal but old; PNG is modern but needs explicit linking. Here's how to use both together.
4 min read
ICO: the universal fallback
Every desktop browser fetches /favicon.ico without you doing anything. It's a container that can hold multiple resolutions.
Windows shortcuts and File Explorer rely on .ico, so even if you don't care about web favicons, ship one for the OS.
PNG: pixel-perfect at any density
PNG renders crisply on high-DPI displays when you link it with <link rel="icon" sizes="...">.
Use 192×192 and 512×512 PNGs for the web manifest, and 180×180 for apple-touch-icon.
Verdict: use both
Ship a multi-size .ico for universal support, plus PNG variants for HD displays and PWA install prompts. Add SVG on top for the sharpest scalable icon.