ICO
What Is An ICO File?
An ICO file is an icon image format commonly used for favicons, Windows desktop icons, and small app icons. One ICO file can contain multiple icon sizes, which lets software choose the right version for a shortcut, tab, app, or interface. That is useful for icons, but less useful when you simply need a normal image preview. Converting ICO to PNG is usually the best choice when transparency matters, while converting ICO to JPG or WebP can be useful for previews, sharing, or web use.
Best For
Favicons, Windows icons, app icons, shortcuts, and small interface graphics.
Watch Out For
ICO can contain multiple sizes. A normal image conversion usually creates one flat image and may not preserve every embedded icon size.