Why doesn't querySelectorAll select all my elements?

querySelectorAll returns an array-like object ( NodeList ), so you can't set properties on all matched elements (like jQuery). You have to iterate through them:

var divs = document.querySelectorAll('div');

for(var i=0; i<divs.length; i++){
    divs[i].style.color = "red";
}

Note: This is different from querySelector , which always returns a single element.

You can write a helper function like:

function qsa(selector, styleProperty, value){
    var divs = document.querySelectorAll('div');

    for(var i=0; i<divs.length; i++){
        divs[i].style[styleProperty] = value;
    }
    return divs;
}

usage:

var divs = qsa('div', 'color', 'red');