Favicon.ico vs PNG
favicon.ico and PNG serve different favicon jobs. ICO is the universal multi-size fallback, while PNG is the modern transparent image format used for explicit browser and mobile icons.
About Favicon.ico vs PNG
favicon.ico and PNG are complementary favicon formats. Use ICO for universal fallback and automatic browser discovery. Use PNG for modern explicit icons, Apple Touch Icons, and clean transparency.
What is favicon.ico? favicon.ico is a favicon file placed at the root of a website, usually at /favicon.ico. It is an ICO container, which means one file can include multiple internal icon sizes such as 16x16, 32x32, and 48x48. Browsers have requested this file for decades, and many still look for it automatically.
What is a PNG favicon? A PNG favicon is a standard PNG image referenced in HTML with a link tag. PNG supports full alpha transparency and works well for files like favicon-32x32.png and apple-touch-icon.png. Each PNG file represents one image size, so sites often provide several PNG files.
ICO vs PNG comparison: | Feature | ICO | PNG | | Browser support | Universal fallback | Modern browsers and devices | | Multiple sizes in one file | Yes | No | | Transparency | Supported but older behavior varies | Strong alpha transparency | | Apple Touch Icon | No | Yes | | Automatic root discovery | Yes for /favicon.ico | No, usually linked in HTML | | Best use | Fallback favicon container | Modern favicon and mobile icons |
Best practice is to use both: serve favicon.ico at the site root and add PNG links for common modern sizes. Use the favicon size guide for exact dimensions, and use the broader favicon format guide when comparing ICO, PNG, and SVG together.