Modernizr is a JavaScript library which is designed to detect HTML5 and CSS3 features in various browsers, which lets JavaScript avoid using unimplemented features or use a workaround such as a shim to emulate them. Modernizr aims to provide this feature detection in a complete and standardized manner.


The logo for Modernizr, a JavaScript library to detect CSS3 and HTML5 capabilities in the browser. The logo shows a pink mark of two quarter-circles, one that is “pixelated” into three large steps, and one that is smooth and rounded.