As you can see, 16px favicons are pixelated as shown below. Thankfully there is an easy fix.
How to make your favicon high pixel density (Retina) compatible.
1. Replace your 16px by 16px favicon with a 32px x 32px favicon at the default location: http://www.yourdomain.com/favicon.ico.
2. That’s it.
You can see our favicon here: http://enrappture.com/favicon.ico. Seems to work, let us know if you see issues.
So if you haven’t updated your favicon, now may be a good time.
*This figure is not particularly accurate, as some sites are not consumer facing. Also, there are probably better ways.