Favicon Generator

For a modern site, almost never — browsers prefer the PNG links in your HTML. It is still worth having at the root, because some feed readers, link previewers and older software request /favicon.ico blindly and show nothing when it 404s. It costs a few kilobytes.

No, and it is a common shortcut that half-works. ICO is a container format with its own header describing the images inside it — a renamed PNG has no such header. The .ico produced here is a real container holding 16, 32 and 48px versions, so the browser picks whichever it needs.

512 × 512 or larger, and square. Everything is scaled down from your original, so a small source gives blurry large icons, and scaling up cannot invent detail that was never there.

Because 16 × 16 is 256 pixels in total, and detailed artwork simply cannot survive it. Favicons that read well are a single letter, a simple mark or a bold silhouette. If your full logo is complex, make a simplified version for the small sizes rather than shrinking it.

Usually yes, so it sits properly on light and dark browser chrome. The exception is a mark that disappears against one of them — a black logo on transparent vanishes in dark mode — in which case give it a solid background shape instead.

No. Every size is drawn and encoded in your browser, and the .ico is assembled here too. A logo that has not been announced yet stays on your machine.