Question 1

Should I use ICO or PNG for my favicon?

Accepted Answer

For maximum compatibility, use both: a favicon.ico (for legacy browsers and bookmarks) and PNG favicons for modern browsers. The ICO format is the only format guaranteed to work everywhere, including older IE versions.

Question 2

What is a multi-size ICO file?

Accepted Answer

A single .ico file can contain multiple images at different sizes (e.g. 16×16, 32×32, 48×48). The operating system or browser automatically selects the best size. Our favicon-multi.ico contains 16, 32, and 48px variants.

Question 3

What size should my favicon be?

Accepted Answer

16×16 for browser tabs, 32×32 for taskbars and bookmarks, 48×48 for Windows desktop shortcuts, and 256×256 for high-DPI displays and Windows application icons. A multi-size ICO covers all cases.

Question 4

How do I create an ICO file?

Accepted Answer

Online: favicon.io, realfavicongenerator.net. CLI: ImageMagick (convert icon.png icon.ico). Node.js: png-to-ico package. Most tools can combine multiple sizes into a single .ico file.

Question 5

Can I use SVG as a favicon?

Accepted Answer

Yes, modern browsers support SVG favicons: <link rel="icon" type="image/svg+xml" href="/favicon.svg">. However, ICO is still needed as a fallback for older browsers and some bookmark managers.

Format	ICO (Windows Icon)
Contains	One or more PNG/BMP images at different sizes
Common sizes	16×16, 32×32, 48×48, 256×256
Used by	Browser favicons, Windows desktop icons
Multi-size	Single .ico can contain all sizes

Sample ICO Files — Favicons & Windows Icons

How to use ICO files

Technical specifications

Frequently Asked Questions

Other image formats