paulirish

What forces layout / reflow

All of the below properties or methods, when requested/called in JavaScript, will trigger the browser to synchronously calculate the style and layout*. This is also called reflow or layout thrashing, and is common performance bottleneck.

Generally, all APIs that synchronously provide layout metrics will trigger forced reflow / layout. Read on for additional cases and details.

Element APIs

Getting box metrics

• elem.offsetLeft, elem.offsetTop, elem.offsetWidth, elem.offsetHeight, elem.offsetParent

sergejmueller

Prolog

Google Chrome Developers says:

The new WOFF 2.0 Web Font compression format offers a 30% average gain over WOFF 1.0 (up to 50%+ in some cases). WOFF 2.0 is available since Chrome 36 and Opera 23.

Some examples of file size differences: WOFF vs. WOFF2

TTF to WOFF2 converting

• http://www.fontsquirrel.com/tools/webfont-generator

hallettj

// It is important to declare your variables.

(function() {
    var foo = 'Hello, world!';
    print(foo);  //=> Hello, world!
})();

// Because if you don't, the become global variables.

(function() {