Convertisseur d'Image en ICO

The ICO format is a special image container used for favicons (the small icon displayed in browser tabs) and Windows application icons. Unlike PNG or JPEG, an ICO file can contain multiple images at different sizes and color depths within a single file. This allows the operating system or browser to select the most appropriate size for the display context -- a 16×16 version for the browser tab, a 32×32 version for the desktop shortcut, and a 256×256 version for the file explorer.

For modern websites, the HTML tag can reference either an ICO file or a PNG file. Using a PNG favicon is simpler (single size, 32×32 or 192×192) and is supported by all modern browsers. However, ICO files are still recommended for maximum compatibility -- older browsers (IE, old Safari) only support ICO favicons. ICO files are also required for Windows desktop applications and UWP (Universal Windows Platform) apps.

The ICO file format has a simple structure: a header specifying the number of images, followed by a directory of image entries (each with size, width, height, color depth, and offset), followed by the actual image data (which can be in BMP or PNG format). Modern ICO files typically use PNG-encoded image data for sizes above 64×64 (better compression) and BMP-encoded data for smaller sizes (better compatibility). Our tool generates ICO files with PNG-encoded images at multiple sizes.

Create a favicon that works at all sizes -- from 16×16 (browser tab) to 256×256 (Windows shortcut). Start with a simple, bold design: a single letter, a simple shape, or a simplified version of your logo. Avoid thin lines, small text, and intricate details that will disappear at 16×16. Test your favicon at 16×16 in a browser tab -- if it's not recognizable, simplify the design. Use high contrast colors that stand out against both light and dark browser tab backgrounds.

For comprehensive favicon support, include: an ICO file with 16×16, 32×32, and 48×48 sizes for legacy browsers; a 180×180 PNG for Apple Touch Icon (iOS home screen); a 192×192 and 512×512 PNG for PWA manifest icons; and a 32×32 PNG as the default favicon. Use the HTML link tags: , , and . Our tool generates the ICO file with multiple sizes from a single source image.