PNG to ICO Converter

ICO is Microsoft's icon format. Unlike a PNG, which holds one picture, an ICO file can hold the same icon at several sizes. Software that displays the icon picks the size it needs: a browser tab takes 16 or 32 pixels, a Windows desktop shortcut a larger one, and high-density screens the bigger versions.

That makes ICO the format for two common jobs. On websites, favicon.ico in the site root is the icon browsers have looked for since the late 1990s, and it still works as a fallback for everything that reads site icons. On Windows, program icons, shortcut icons and folder icons are ICO files.

If you have a logo as a PNG, converting it is the quickest way to an icon that works in both places, with the transparent background kept at every size.

Before converting, make sure the PNG is square. A wide logo with a wordmark next to the symbol does not fit an icon well; crop it to the symbol with Crop Image or prepare a square version in your design tool.

Both formats are lossless and both support full transparency. In fact, the larger images inside a modern ICO file are often stored as PNG data. The difference is the container: ICO adds a small directory that lists each size it holds, which is what lets Windows and browsers choose.

Quality depends almost entirely on the source. Each smaller size is scaled down from your PNG, which keeps edges smooth. A PNG smaller than 256 pixels would have to be enlarged for the biggest icon, so it looks soft. For small sizes, thin lines and small text vanish, so a simple, bold design gives the best favicon.

Transparent corners and soft drop shadows survive the trip because each image in the ICO keeps the alpha channel. Check the result on a dark background as well as a light one: a dark logo without an outline can vanish on dark taskbars and browser themes.

Rename the downloaded file to favicon.ico and upload it to the root folder of your site, so it is reachable at your domain followed by /favicon.ico. Then add the line below to the head of your pages. The sizes value any is the convention for an ICO that bundles several resolutions, as described in the HTML standard's rel=icon section.

Browsers cache favicons aggressively. If the old icon still shows after uploading, open the favicon address directly and reload it, or test in a private window.

Google Search shows your favicon next to your pages in results. Its favicon guidelines require a square icon of at least 8 × 8 pixels and recommend one larger than 48 × 48, and they list ICO among the supported formats. An ICO with all sizes up to 256 pixels meets those rules.

For Windows, Microsoft recommends that apps include at least 16, 24, 32, 48 and 256 pixel versions, and notes that Windows looks for an exact size first and otherwise scales down the next larger one. The preset here includes 16, 32, 64, 128 and 256, so the 256 px image ensures there is always a larger size to scale from.

To make a single-size icon for a program that asks for one, choose that size under Icon sizes. Up to 20 PNGs can be converted per batch.

For a Windows shortcut or folder, right-click it, open Properties and choose Change Icon, then browse to the ICO. Keep the file in a permanent place, because Windows reads it from there every time. If you need other image formats from the same logo, the Image Converter page covers them.