Upload your ICO file to preview all embedded images, analyze layers, check dimensions, transparency, and platform compatibility.
Essential for browser favicons, toolbar icons, and address bar display.
Desktop icon sizes for Windows Explorer, Start Menu, and file shortcuts.
High-resolution icons for modern displays, macOS, and Windows 10/11.
The ICO file format is a container format developed by Microsoft for storing icons in Windows. Unlike standard image formats, a single ICO file can contain multiple images at different sizes and color depths, making it ideal for icons that need to display correctly at various resolutions.
Each image within an ICO file is stored as either a BMP (bitmap) or PNG compressed image. Modern ICO files typically use PNG compression for larger sizes (48×48 and above) to reduce file size while maintaining quality, and BMP for smaller sizes to ensure maximum compatibility.
When Windows or a web browser needs to display an icon, it automatically selects the most appropriate size from the ICO file. This ensures your icons look crisp and professional whether displayed as a tiny favicon in a browser tab or a large desktop shortcut.
Pro tip: Need to modify your ICO file? Use our Icon Resizer to add new sizes, remove unwanted layers, or convert PNG to multi-size ICO.
ICO files can contain multiple images of different sizes (16×16, 32×32, 48×48, etc.) in a single file.
Each image can be stored as BMP (original format) or PNG (modern, with better transparency).
32-bit images have 24 bits for color and 8 bits for alpha channel (transparency).
Operating systems automatically select the most appropriate size for the display context.
The analyzer shows comprehensive details including all embedded image sizes, internal formats (BMP/PNG), color depths, transparency support, file size information, quality scores, and compatibility recommendations for different platforms.
Yes! Our ICO viewer displays detailed information about all embedded icon sizes and formats. You can see the specifications for 16×16, 32×32, 48×48, 64×64, 128×128, 256×256 and any other sizes contained in your ICO file.
Yes, our ICO analyzer and viewer tool is completely free to use. There are no registration requirements, usage limits, or hidden fees. Simply upload your ICO file and get instant analysis results.
No, your files are processed temporarily and automatically deleted after analysis. We do not store, share, or retain any uploaded ICO files. The analysis happens in real-time and files are removed from our servers immediately after processing.
After analyzing your ICO file, you can use our Icon Resizer tool to add new sizes, remove existing layers, or create a new multi-size ICO from a PNG image. For creating ICO files from scratch, try our PNG to ICO converter.