CSS Summit, Environments for Humans 2015

Sarah Drasner, Senior UX Engineer at Trulia


@sarah_edo : twitter || @sdras : codepen


  1. Crisp on any display
  2. Less HTTP requests to handle
  3. Easily scalable for responsive
  4. Small filesize if you design for performance
  5. Easy to animate
  6. Easy to make accessible
  7. Fun! 

This pen.

Before we get started:

Animation Performance!

SVG Sprites

Start with this technique from Joe Harrison

Technique #1:

Splash with Step()

Step Animation

Of all web-based animation techniques, step animation most closely resembles old hand-drawn cel animation.


Let's use this to our advantage.

3 of 21 frames.

Shooting on twos.

This pen.

Large Sprite and animate the background position.

Keep it simple.

@keyframes splashit {
        100% { background-position: 0 -3046px; }

.splash {
  background: url(‘splash-sprite2.svg’);
  animation: splashit 1.8s steps(21) infinite;

/* fallback */
.no-svg .splash {
  background: url(‘splash-sprite2.png’);



  • Fallback w/ modernizr
  • Fallback to a png equivalent
  • Fallback with the picture element (+ polyfill)
    Sara Soueidan's article
  • Recommended: look at your analytics

2 ways to make this.

Illustrator, with a template:

  • Object → Path → Split Into Grid
  • View → Guides → Make Guides
  • Draw and then copy paste and align, change drawing slightly
  • Can also easily export png fallback

Works with Sketch, too.

2 ways to make this.

In an SVG editor with Grunticon

  • Draw drawing in SVG editor, save off one by one
  • Can also draw on paper and scan
  • Use grunticon
  • It makes the fallback for you

After export, before implementation:


Technique #2:

Rolling Sprite Background

without Step()

Take the steps() out

The background rolls through...

Let's use this to our advantage.

.area {
  width: 600px;
  height: 348px;

.fore, .mid, .bk, .container { @extend .area; }

Extend to keep it DRY

.fore {
  background: url(‘fore.svg’);
  animation: bk 7s -5s linear infinite;

.mid {
  background: url(‘mid.svg’);
  animation: bk 15s -5s linear infinite;

.bk {
  background: url(‘bkwalk2.svg’);
  animation: bk 20s -5s linear infinite;

@keyframes bk {
  100% { background-position: 200% 0; }

Z-index for parallax, consistent bk position, 

different length of animation in seconds.

Technique #3:

Modern Day Book of Kels

Illustration with SVG Sprite

Make it a responsive svg animation sprite

This pen.

That whole SVG and animation was
8KB Gzipped.

Compare to using text with photos to illustrate an article.

CSS Animation

[class^="star"] {
  animation: blink 2s ease-in-out infinite both;

[class^="dot"] {
  animation: blink 5s -3s ease-in-out infinite both;

@keyframes blink {
  50% { opacity: 0; }

No width and height for the SVG itself, instead define it in css

.initial { 
  width: 50%;
  float: left;
  margin: 0 7% 0 0;

We're using percentage here, but we could also use flexbox.

viewBox="0 0 490 474" preserveAspectRatio="xMidYMid meet"

Define smaller viewbox, put in preserveAspectRatio (though this is also the default)


+ Adjust initial object, affects animation

[class^="mountain"], [class^="grass"] {
  transform: skew(2deg);

@media screen and ( max-width: 500px ) {
  [class^="mountain"], [class^="grass"] { 
    transform: skew(1.5deg);

!important part


You can do this, you know this already, it applies to all animation, even javascript

!important part

Viewbox shift with JavaScript

var shape = document.getElementById("svg");

// media query event handler
if (matchMedia) {
        var mq = window.matchMedia("(min-width: 500px)");
// media query change
function WidthChange(mq) {
        if (mq.matches) {
            shape.setAttribute("viewBox", "0 0 490 474");
        else {
            shape.setAttribute("viewBox", "0 490 500 500");

Acts like a window to show and hide the requisite parts of the sprite

Technique #4:

One Scalable SVG with

Hidden Information

Sometimes for complex animations, we need to use JavaScript. GSAP, to be exact.

here's why...


(I don't work for them and they don't pay me.)

Solves cross-browser inconsistencies

Bad transform origin bug on rotation.

More in this CSS-Tricks article.




Safari (zoomed)


  • stack tweens
  • set them a little before and after one another
  • change their placement in time
  • group them into scenes
  • add relative labels
  • animate the scenes!
  • make the whole thing faster, move the placement of the whole scene, nesting

All without recalculation!

The issue with longer CSS animations:

This pen.

Other cool things

for complex animation

  • Motion along a path (widest support)
  • Draggable
  • CSS Properties
  • Draw SVG- make an SVG look like it draws itself.

Percentage based transforms on SVG!

get excited.

This pen courtesy of GreenSock.

So we can do stuff like this, All fully responsive in every direction

Animation As Information

  • Animation must be designed
  • Helps with context-shifting
  • Invisible animation- check out Val Head's awesome "All the Right Moves"
  • Comply with branding
  • Animation for a company means having a motion design language, like Google Material Design
  • Consistent on mobile, or a fallback to a light version

This pen.

This pen.

Motion on the web:

Fun! But also, USEFUL!

Technique #5:

Responsive Design for an

Animated Infographic

Pretty close to Technique #3, 

Kels Illustration

Revisiting old approaches

Responsive Animated Infographic

Three sources with detailed analysis showing lead improvements


(one source example, The Whole Brain Group)

  • increased traffic to their website by over 400%
  • lead increase by almost 4500%
  • the number of new visitors to their site to almost 78%


  • Not responsive- tipping point: Tim Kadlec
  • Not updated to current context
  • ^ Especially design

All posts older than 2 years.

What Happened?

This pen.


Change the viewbox in JavaScript like we did before:


Media queries for layout, and fallback with Modernizr:

/* media query example element, mobile first */
@media (max-width: 825px) {
  .container {
    width: 100%;
@media (min-width: 826px) {
  .container {
    width: 825px;

/* fallback */
.inlinesvg .fallback {
  display: none;

.no-inlinesvg .fallback { 
  width: 500px;
  height: 500px;
  display: block;


Title and associative aria tags: (WIP)

<svg aria-labelledby="title" id="svg" xmlns="" viewBox="0 0 765 587">
<title id="title" lang="en">Circle of icons that illustrate Global Warming Solutions</title>

You can also add a title for elements in the SVG DOM

This resource, with support charts.

Also, this article by Dudley Storey.

Social Coding sites help you learn

Fun. Remember fun?

(I don't work for them and they don't pay me)

  • Codepen
  • JS Fiddle
  • Dabblet

People you should know about

  • Val Head
  • Sara Soueidan
  • Rachel Nabors
  • Tiffany Rayside
  • Chris Gannon
  • CJ Gammon
  • LegoMushroom
  • Ana Tudor
  • David Walsh Blog
  • CSS-Tricks
  • Amelia Bellamy-Royds
  • Taylor Hunt
  • Dudley Storey
  • CSS Animation Rocks
  • GreenSock
  • Dennis Gaebel
  • I Hate Tomatoes (Petr Tichy)
  • Lucas Bebber
  • Joni Trythall
  • Jake Albaugh


Thank you!

Sarah Drasner

@sarah_edo on twitter

@sdras on codepen

These Slides:

SVG Sprites for Animation

By sdrasner

SVG Sprites for Animation

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