PNG to ICO Converter

When you need PNG to ICO conversion

ICO is the icon format: it is used for website favicons, Windows application icons, and custom folder icons. For everyday image viewing or publishing, ICO is not needed. But if you are building a website and want an icon in the browser tab, developing a Windows application, or want to put a custom icon on a folder, ICO is exactly what you need.

A PNG with a transparent background is the best source for this task. Transparency transfers to ICO correctly, so the icon will look good on both light and dark interface themes.

Transparency: why PNG is the ideal source

Icons almost always need a transparent background - the icon must fit into any surrounding rather than sitting on a white rectangle. PNG supports full transparency with smooth transitions: soft edges, shadows, and anti-aliasing along the outline. All of this transfers to ICO without loss.

Converting a JPG or an image without transparency to ICO will produce an icon with an opaque background. On a dark desktop or dark browser theme, it will look like a light square with a picture inside. A PNG with a removed background gives exactly the result expected from a professional icon.

Sizes and uses

ICO is a container that can hold multiple versions of the same icon at different sizes. The browser or operating system picks the one it needs depending on the context. A small size is needed for the browser tab, a larger one for a folder on the desktop.

For a favicon, one size is usually enough - 32x32 or 48x48 pixels. For a Windows application icon, 256x256 is recommended so the system can scale it down without quality loss.

For a good result, use a source PNG of at least 256x256 pixels with a simple, readable image. Fine details, thin lines, and small text become illegible at heavy scaling - keep only the key elements.

Favicon for a website

A favicon is the small icon displayed in the browser tab next to the page title, in bookmarks, and in the address bar. It increases site recognition and helps the user quickly find the right tab among many open ones.

The simplest way to add a favicon is to place a favicon.ico file in the root of your site. Most browsers find it automatically. To specify it explicitly in your page code, add a line to the head block:

<link rel="icon" href="/favicon.ico">

Modern browsers also accept PNG directly, without converting to ICO. But ICO remains the more compatible option, especially for older browsers and corporate environments.

Icons for Windows

Windows software developers embed ICO in executable files - the icon is displayed in Explorer, the Start menu, and the system tray. Users can also replace standard folder icons with custom ones through shortcut or folder properties. For this, Windows only accepts ICO.

Transparency matters to the system: modern Windows uses dark and light themes, and an icon without a transparent background will look outdated.

What to check

Reduce the source PNG to 32x32 manually in any viewer and assess whether the image remains recognizable. If not, simplify the design: remove fine details, enlarge key elements, add contrast.

After conversion, check the icon on both a dark and a light background. Make sure transparency works correctly and there is no unwanted white or black outline around the object.

Format limitations

ICO is not intended for regular images - it is not a photo format and not a format for storing illustrations. It is used only for icons at fixed small sizes. The maximum image size inside an ICO is 256x256 pixels. For other tasks - publishing, printing, editing - use PNG.

If you are creating icons for macOS applications, a different format is used there - ICNS. ICO is not suitable for that purpose.

Related tasks

If you need not an icon but simply a smaller image, use PNG to JPG or keep PNG. For creating a PDF with illustrations, PNG to PDF works. For a PNG version optimized for fast website loading, consider PNG to WebP.