Can one ICO hold multiple sizes?

The format supports it; the tool exports one size at a time. Ship 32 first and add 16/48 references later if needed.

Can I just use a PNG as favicon?

Modern browsers allow it, but ICO remains the safest baseline. Use ICO with PNG as fallback.

Edges look fuzzy in the tab — fix?

Too much detail or non-integer scaling in the source. Redesign simplified and export from a proper square.

Formats & playback 5 min read

Making a Favicon: From Logo to ICO Icon

Favicons are easy to make and easy to blur — the culprit is usually the source image, shrunk from a detailed logo to 16 pixels.

What ICO actually is

ICO is a container format holding several bitmap sizes — 16, 32, 48 — in one file; the browser picks the best fit. Modern browsers also accept plain PNG favicons, but ICO has the widest compatibility.

Start from a clean square source: a 256px-plus transparent PNG, then export each size you need from it.

Why 16px looks mushy

16 pixels is 256 pixels total — no room for detail. Complex logos necessarily collapse; that is information theory, not a bad tool.

The fix is a simplified mark: drop text, keep the shape, thicken outlines. Professional favicons are redesigned minimal versions, not scaled-down logos.

Choosing sizes

Browser tabs use 16 or 32; desktop shortcuts use 32 or 48. The tool exports one size per run — generate separately as needed, or make 32 your universal fallback.

Transparency matters: favicons sit on both light and dark browser themes, and a white box ruins dark mode. Background prep in the PNG/JPG guide.