My Profile Photo

Rich Werden

A simple site for Rich to write about code and archive some completed projects for future reference...

#TIL: CSS3 Vendor-Prefix Function

As I am pretty into transitions and animations being core to contemporary user-experience, I think about all of the ‘gotchas’ with vendor-prefixing that is sometimes required by ‘older’ or not-that-older browsers…

Update: Auto-Prefixer

  • Auto-Prefixer: Check out this repo/site for a well maintained and highly recommended build tool as well as a simple copy-pase tool for adding vendor prefixes.
  • Do it on build: Since most sites are going to be run through a build step, you might as well use that step to compile your vanilla CSS / SASS / SCSS into brower-prefixed forests. There are grunt libs and gulp libs, and of course Webpack versions.
  • Use a Library: - You could include something like prefixfree which is a 2k gzip’d file that will supposedly solve all issues. YMMV
  • Do it as you code: Of course, after writing this, I found an editor plugin for VS-Code as well as [Sublime-Text][st3plug] which will automate the prefixing as you write. Problem with doing things directly like this is that the resulting code will be a mess to read!

Original Post

I came across this code snippet and some variations thereof with a function for determining what [if any] prefix a given browser\vendor requires1. Once you figure that out, you can do what you will via JS to apply the arguments you’ve come up with.

function getCSSPrefixed(cssProp){
    var css3vendors = ['', '-moz-','-webkit-','-o-','-ms-','-khtml-']
    var root = document.documentElement
    function camelCase(str){
        return str.replace(/\-([a-z])/gi, function (match, p1){ // p1 references submatch in parentheses
            return p1.toUpperCase() // convert first letter after "-" to uppercase
    for (var i=0; i<css3vendors.length; i++){
        var css3propcamel = camelCase( css3vendors[i] + cssProp )
        if (css3propcamel.substr(0,2) == 'Ms') // if property starts with 'Ms'
            css3propcamel = 'm' + css3propcamel.substr(1) // Convert 'M' to lowercase
        if (css3propcamel in
            return css3propcamel
    return undefined

I’ve seen a couple of variations on the code above, but basically they all do they same approach - Take a list of possible names and keep trying the different vender prefixes until one of them works. Now, as transitions are pretty standardized, using vendor prefixes is becoming less and less necessary in production, but with animations and transforms, maybe not so much so. Especially if yaknow, if your audience has older devices and you want to make sure things work across the board…

var transformName = getCSSPrefixed('transform') 
// Sets transformName to 'transform' or one of the variants, such as '-moz-transform', '-webkit-transform-', etc

var transitionName= getCSSPrefixed('transition') // as above

The example of using javascript to actually apply the transition names en-masse are shown in their example codepen.

Personally, my brain can’t hardly wait to futz with animation @keyframes affecting CSS[4?] perspective:1 values…

  1. Yep. It’s coming. The cousin of 3D Transforms -  2