PNG to ICO

PNG is the natural source for icons: it is lossless and keeps transparency, so a logo on a transparent background becomes an icon that sits cleanly on any browser tab, taskbar or desktop. This converter packs a PNG into a standard .ico file with as many sizes as you need, ready to use as a favicon or a Windows application, shortcut or folder icon.

Preparing the PNG

The best source is a square PNG of 256 × 256 pixels or larger with a transparent background and the subject filling most of the area. If your PNG is wider or taller, the converter still works: it fits the image inside the square and adds transparent space, never cropping. For a bolder icon, crop it to a square first with Crop Image.

Selecting sizes

Each chip adds one picture size to the file. Browsers use 16 and 32 pixels for tabs, bookmarks and history; Windows uses 16, 24, 32 and 48 in Explorer, the taskbar and menus, and 256 for large and extra-large icon views. The default 16, 32, 48 and 256 covers almost everything; add 24 and 64 for the most polished Windows result. At least one size always stays selected.

How the small sizes are made

Each size is produced from your PNG by reducing it in halving steps with high-quality smoothing, then centered on a transparent square of exactly that size. This keeps edges smooth and avoids the shimmering artifacts of a single, large reduction. Thin lines and small text may still disappear at 16 pixels, which is a limit of the size, not the converter.

Designing for 16 pixels

The tiniest icon matters most, because it is what people see in browser tabs. Use a strong silhouette, high contrast and at most one or two shapes. Many brands use only the first letter or the symbol of their logo for the favicon. If the full logo does not read at that size, make a simplified PNG, convert it with just the 16 and 32 sizes, and use the full logo for a separate large icon.

Transparency in every size

Every image inside the ICO keeps the PNG’s alpha channel, including soft edges. The icon therefore looks right on light and dark browser themes, on any desktop wallpaper and in dark-mode taskbars.

Checking the result

Open the .ico in Windows Explorer and switch the view between small, medium and large icons; you will see the different sizes appear. In a browser, upload it to your site and look at the tab in light and dark themes.

Installing as a favicon

Save the file as favicon.ico in the root of the website, or reference it with a link tag. Browsers cache favicons aggressively, so a changed icon can take a while to appear; a hard refresh helps.

Installing on Windows

For a shortcut, open Properties and choose “Change Icon”. For a folder, use Properties, Customize, “Change Icon”. App frameworks such as Electron or .NET accept the .ico in their build settings.

Related tools

The Favicon Generator produces a complete set including PNG favicons and an Apple touch icon. For vector logos, SVG to ICO renders each size directly from the shapes. To pull PNGs back out of an icon, use ICO to PNG.