Get the CSS transition duration of a DOM element, cross-browser. without jQuery.

get-transition-duration.js

// based on http://stackoverflow.com/a/13008597
function getTransitionDuration ( element, with_delay )
{
	var prefixes = ' webkit moz ms o khtml'.split( ' ' );
	var result   = 0;
	var duration, delay, prefix;

	for ( var i = 0; i < prefixes.length; i++ )
	{
		prefix = prefixes[i] + '-';

		if ( prefixes[i] === '' )
		{
			prefix = '';
		}

		duration = element.style[ camelCase( prefix + 'transition-duration' ) ];

		if ( duration )
		{
			duration = ( duration.indexOf( 'ms' ) >- 1 ) ? parseFloat( duration ) : parseFloat( duration ) * 1000;

			if ( with_delay )
			{
				delay = element.style[ camelCase( prefix + 'transition-delay' ) ];

				if ( delay )
				{
					duration += ( delay.indexOf( 'ms' ) >- 1 ) ? parseFloat( delay ) : parseFloat( delay ) * 1000;
				}
			}

			result = duration;

			break;
		}
	}

	return result;
}

// based on http://stackoverflow.com/a/10425344/229189
function camelCase ( input )
{
	return input
		.toLowerCase()
		.replace(
			/-(.)/g,
			function ( match, group_1 )
			{
				return group_1.toUpperCase();
			}
		);
}