Convert PNG to ICO Favicon

How to convert PNG to ICO — 3 steps

1. 1

   Add your PNG

   Start from a square image with a transparent background. A source around 256×256 or larger gives the converter enough detail to generate every icon size cleanly.

2. 2

   Pick the icon sizes

   An ICO file can hold several resolutions at once. Including 16, 32, and 48 pixels covers browser tabs and Windows shortcuts; adding 256 covers large icon views in File Explorer.

3. 3

   Download the ICO

   Save the file. For a website favicon, place it at the root of your domain as favicon.ico, where browsers look for it automatically.

An ICO is a container, not a single image

This is the part that surprises people coming from ordinary image formats. A PNG holds one picture at one resolution. An ICO holds a set of images at several resolutions inside a single file, and whatever displays it picks the size closest to the space available. That is why a well-made icon looks sharp both as a 16-pixel browser tab and as a large tile in File Explorer, while a resized screenshot looks muddy in both.

The sizes that still matter in practice are 16×16 for browser tabs and small list views, 32×32 for desktop shortcuts and standard Windows icon views, 48×48 for medium icon views, and 256×256 for large icon and preview panes. Including all four costs very little file size and means the operating system never has to scale an image itself — which it does poorly, especially when scaling down.

Your source image should be square. An ICO is displayed in a square slot, so a rectangular source is either padded or squashed, and neither result is what you designed. Crop to a square before converting rather than letting the conversion decide for you.

Designing something that survives at 16 pixels

The common mistake is to take a detailed logo and shrink it. At 16 pixels a logo has roughly 256 pixels in total to work with — less than a single letter of this sentence occupies on screen. Fine strokes vanish, gradients turn to mud, and any wordmark becomes an illegible smear. Icons that read well at that size are built from one bold shape, high contrast against the background, and at most a single character of text.

The practical approach is to simplify rather than scale: take the strongest element of your brand — a monogram, a symbol, the distinctive part of the mark — and build the icon from that alone. Then check it at actual size rather than zoomed in, because an icon that looks sparse at 400% is usually the one that reads correctly in a real browser tab.

Transparency matters too. Browser tabs and Windows themes vary between light and dark, so an icon with a baked-in white background will sit in a visible white box for anyone using a dark theme. Start from a PNG with a genuinely transparent background, and make sure the shape itself has enough contrast to be visible against both light and dark surroundings.

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