[javascript] How to detect chrome and safari browser (webkit)

Instead of detecting a browser, you should rather detect a feature (whether it's supported or not). This is what Modernizr does.

Of course there are cases where you still need to check the browser because you need to work around an issue and not to detect a feature. Specific WebKit check which does not use jQuery $.browser:

var isWebKit = !!window.webkitURL;

As some of the comments suggested the above approach doesn't work for older Safari versions. Updating with another approach suggested in comments and by another answer:

var isWebKit = 'WebkitAppearance' in document.documentElement.style;