PNG to ICO: A Favicon That Looks Sharp at 16px

Browsers and operating systems request different icon sizes. If the file only contains a 256×256 image, Windows and old browsers downscale it themselves — and small details disappear.

The sizes that matter

• 16×16 — browser tab, bookmarks bar
• 32×32 — taskbar, high-DPI tabs
• 48×48 — desktop shortcuts
• 256×256 — modern high-DPI and store listings

A multi-size ICO stores all of them, so each context gets a purpose-drawn version instead of a resample.

Design for the smallest size first

• Keep one clear shape; thin lines vanish at 16px
• Avoid text — it becomes unreadable
• Leave a little padding so the icon does not touch the edge
• Use transparency, not a white square, unless the brand needs a background

How to convert

1. 1Start with a square PNG, ideally 512×512 or 256×256.
2. 2Open PNG to ICO and upload it.
3. 3Download the generated `.ico` — it contains multiple sizes.
4. 4Place it at the site root as `favicon.ico` and reference it in the page head.

Frequently asked questions

Can I use SVG instead?

Modern browsers accept SVG favicons and they scale perfectly, but `.ico` is still needed for older browsers and Windows shortcuts. Ship both.

Why does my favicon look blurry in the tab?

The browser is downscaling a large image. A multi-size ICO includes a 16×16 and 32×32 version, so it renders crisp.

Is the ICO transparent?

Yes, if the source PNG has transparency. Convert to RGBA before saving when the background must stay clear.