| Format introduction | The ICO file format is an image file format for computer icons in Microsoft Windows. ICO files contain one or more small images at multiple sizes and color depths, such that they may be scaled appropriately. In Windows, all executables that display an icon to the user, on the desktop, in the Start Menu, or in Windows Explorer, must carry the icon in ICO format. | WebP is an image format employing both lossy and lossless compression. As a derivative of the VP8 video format, it is a sister project to the WebM multimedia container format. WebP-related software is released under a BSD license. |
| Technical details | An ICO file is made up of an ICONDIR ("Icon directory") structure, containing an ICONDIRENTRY structure for each image in the file, followed by a contiguous block of all image bitmap data (which may be in either Windows BMP format, excluding the BITMAPFILEHEADER structure, or in PNG format, stored in its entirety). | Google has proposed using WebP for animated images as an alternative to the popular GIF format, citing the advantages of 24-bit color with transparency, combining frames with lossy and lossless compression in the same animation, and as well as support for seeking to specific frames. |
| File extension | .ico | .webp |
| MIME | image/x-icon, image/vnd.microsoft.icon | image/webp |
| Developed by | Microsoft | Google |
| Type of format | Graphics file format for computer icons | Image format, Lossless/lossy compression algorithm |
| Associated programs | Axialis IconWorkshop, IcoFX, IconBuilder, Microangelo Toolset, Greenfish Icon Editor Pro, GIMP, ImageMagick, IrfanView, ResEdit. | Google Chrome, Opera, Picasa, PhotoLine, Pixelmator, ImageMagick, XnView, IrfanView, GDAL |
| Wiki | https://en.wikipedia.org/wiki/ICO_(file_format) | https://en.wikipedia.org/wiki/WebP |