The favicon sizes that actually matter

Search for a favicon guide and you will find lists demanding sixteen files. Most of that is cargo cult. Browsers settled on a small set years ago, and the rest is leftover advice from a time when phones and desktops disagreed more than they do now. Here is what a site actually needs.

The core three

A favicon.ico holding 16, 32, and 48 pixels covers nearly everything a desktop browser does. The 16 shows in a busy tab. The 32 covers high-DPI tabs and the bookmark bar. The 48 turns up in a few Windows spots. Pack all three into one .ico and the desktop is handled.

If you remember one thing, remember that .ico is a bundle. It is not a single image with an old extension. It carries several sizes at once, and the browser picks.

The mobile pair

Phones ignore the .ico and want PNGs. Two matter:

• apple-touch-icon.png at 180x180, for when someone saves your site to an iPhone home screen.
• A 192 and a 512 PNG, for Android and for any site that can be installed as an app.

The 512 does double duty as the splash image for installed web apps, so it is worth rendering cleanly rather than upscaling a smaller one.

The one that is optional but nice

A single SVG favicon lets modern browsers scale your icon to any size and even swap colors in dark mode. It is a nice touch. It is not a replacement, because plenty of places still read the .ico first.

What you can skip

The old 57, 72, and 114 pixel Apple sizes. The Microsoft tile images, unless you specifically care about pinned tiles in Windows. The endless PNG variants some generators still emit. None of them hurt. None of them earn the clutter either.

Doing it in one pass

Rather than export each size by hand, hand a single square image to the favicon generator. It renders the core set, writes the .ico, and prints the exact link tags to paste. If you already have an .ico and want to see what is inside, the ICO to Image tool opens it up size by size. All of it starts on the ConvertICO home page, where you drop a picture and get an .ico back.

So the whole job comes down to a favicon.ico plus a couple of PNGs.