ICO to GIF Converter

The ICO format is an image container specifically designed for Microsoft Windows to store icons for executable files, folders, and applications. Introduced with Windows 1.0, it can encapsulate multiple raster images of varying dimensions and color depths (specifically BMP or PNG frames) within a single file to support dynamic scaling across different display resolutions. The structure comprises an ICONDIR header referencing one or more ICONDIRENTRY directory entries, allowing the operating system to select the appropriate 16x16, 32x32, or 48x48 pixel resource based on the current UI scaling settings.

ICO files are natively supported by the Microsoft Windows operating system, which automatically renders them in the File Explorer and taskbar. On macOS, Apple Preview handles the format natively. For editing or detailed inspection of the contained bitmap layers, raster graphics editors such as GIMP, Adobe Photoshop (via plugin), or Paint.NET are required. Web browsers also natively render ICO files when they are designated as favicons.

The Graphics Interchange Format (GIF) is a bitmap image format developed by CompuServe in 1987, distinguished by its use of the Lempel-Ziv-Welch (LZW) lossless data compression algorithm. It supports up to 8 bits per pixel, allowing a palette of 256 distinct colors selected from the 24-bit RGB color space. The GIF89a specification, introduced in 1989, added support for transparent backgrounds, animation delays, and application extensions, establishing it as a standard for simple web animations and low-color graphics.

GIF files possess near-universal compatibility and can be opened natively by all modern web browsers (Chrome, Firefox, Safari, Edge) and default operating system viewers like Microsoft Photos and Apple Preview. No third-party software is typically required for viewing. For editing frame-by-frame animations or modifying color palettes, raster graphics editors such as GIMP, Adobe Photoshop, or online tools like Ezgif are required.