PNG to ICO Converter

The ICO format was designed decades ago specifically to hold several versions of the same icon at different sizes inside one file, because the places that display favicons need different resolutions for different contexts: a browser tab wants something tiny and legible at 16×16, a taskbar or shortcut wants more detail at 32 or 48 pixels, and a high-density display or an app store listing wants a much larger version for a crisp result. A plain PNG renamed to .ico is not a valid multi-size icon and will often display incorrectly or not at all in software that expects the real format.

This builds six sizes — 16, 32, 48, 64, 128 and 256 pixels square — into a single properly structured ICO, so whichever context reads the file gets to pick the resolution that fits.

Since every size inside an ICO must be a perfect square, a source image that isn’t square — a wide logo, a rectangular banner — cannot simply be squashed into that shape without visibly distorting it. Instead, the image is centred within each square size and scaled to fit, with the surrounding area left transparent, so proportions stay correct and nothing looks stretched.

For the sharpest possible result, especially at the smallest 16-pixel size where detail disappears fast, starting from an already-square source image with simple, high-contrast shapes gives the cleanest favicon — a detailed logo with fine text often becomes an illegible smudge at 16 pixels no matter how it is generated.

The most common placement is a file named favicon.ico at the root of a website, which most browsers check automatically even without any HTML pointing to it — though adding an explicit <link rel="icon" href="/favicon.ico"> tag in the page head is the more reliable, standards-compliant way to declare it. Some newer setups use PNG or SVG favicons declared directly in HTML instead of ICO, but the multi-size ICO remains the format with the broadest compatibility across older browsers, Windows shortcuts, and various desktop and build tooling that still expects it by name.

The image is resized into each of the six required sizes and packed into the ICO container locally in your browser, so an unreleased logo or brand asset never needs to be sent anywhere just to produce a favicon. The result is ready to download as soon as processing finishes, with no account, no watermark, and nothing retained once you leave the page.