Negative values are also allowed. If using negative values, the animation will start as if it had already been playing for N seconds. In the following example, the animation will start as if it had already been playing for 2 seconds:.
The animation-iteration-count property specifies the number of times an animation should run. The following example uses the value "infinite" to make the animation continue for ever:. The animation-direction property specifies whether an animation should be played forwards, backwards or in alternate cycles.
The following example uses the value "alternate" to make the animation run forwards first, then backwards:. The following example uses the value "alternate-reverse" to make the animation run backwards first, then forwards:.
The animation-timing-function property specifies the speed curve of the animation. CSS animations do not affect an element before the first keyframe is played or after the last keyframe is played. The animation-fill-mode property can override this behavior. The animation-fill-mode property specifies a style for the target element when the animation is not playing before it starts, after it ends, or both.
The backwards animation is applied to every even -number child, while the forwards animation is applied to every odd -number child. The animations we've just created are made with an initial ' from ' starting position, with no vertical position or rotation adjustment. The ' to ' position is the final state of the animation, which sets the elements with an adjusted vertical position and rotation state. Slightly different ending settings are used for both animations to avoid the text becoming unreadable due to overlap in mixed animations.
When animating with CSS sometimes a dead simple approach is necessary. And there are few simpler animation methods than the flip book. Using steps as our timing function, we are able to replicate this effect. While this might sound choppy and directly contradict our mission to maintain fluidity, with the right pacing it can feel just as seamlessly organic. So how does it work?
In this case, each step will be one second long, immediately moving to the following one-second frame with no transition between. We can incrementally iterate through a sprite sheet and animate frame-by-frame just like a flip book. By defining frames of equal size but compiling them onto a single horizontal or vertical image, we can set this image as an element background and define a pixel or percentage background position as an end point to our animation, allowing a single step for each frame.
The sprite sheet will then shift and populate the element frame by frame with a fresh background image based on its position. In this case some sets of animated legs appended to some text characters. Again, note that the duration is relatively speedy at less than one full second for 32 total frames.
Note that the vertical positioning of the image is consistent throughout, which tells us that the sprites are horizontally stretched across the image, which is px in total width. Check out this Codepen below. With a well-crafted sprite sheet and an appropriate animation duration you now have a smooth animation able to convey complex motions. The CSS bubble animation that features on 7UP is a beautiful example of carrying a brand theme through into the website design.
The first animation changes the opacity of the bubble and moves it vertically in the view box; the second creates the wobbling effect for added realism. The offsets are handled by targeting each bubble and applying a different animation duration and delay. In our SVG we create two layers of bubbles: one for the larger bubbles and one for the smaller bubbles. Inside the SVG we position all of our bubbles at the bottom of the view box. In order to apply two separate animations to our SVGs, both utilising the transform property, we need to apply the animations to separate elements.
CSS has a powerful animation engine and really simple code in order to produce complex animations. In order to create a wobbling effect, we simply need to move or translate the bubble left and right, by just the right amount — too much will cause the animation to look too jaunting and disconnected, while too little will go mostly unnoticed.
Experimentation is key with when working with animation. We start by applying an opacity value to the bubbles and the will-change property in order to utilise hardware acceleration. We want to keep all the animation times and delays within a couple of seconds of each other and set them to repeat infinitely. Lastly, we apply the ease-in-out timing function to our wobble animation to make it look a little more natural.
A subtle scrolling mouse animation can give direction to the user when they first land on a website. At 0 and 20 per cent of the way through our animation, we want to set the state of our element as it begins. The last thing we need to do is drop the opacity in order to fade out our circle. The animation properties are fairly self-explanatory. The cubic-bezier timing function is used to first pull the circle back before dropping it to the bottom of our mouse shape; this adds a playful feel to the animation.
The Garden Eight website uses a common animation technique whereby text appears to be written out. To achieve the effect, we turn to SVG.
There are two approaches here: convert the text to paths in order to animate them or use SVG text. Both approaches have their pros and cons.
Start by creating our keyframe animation. The only function we need it to perform is to change the stroke-dashoffset. We set the stroke-dasharray , which will create gaps in the stroke.
We want to set our stroke to be a large enough value to cover the entire element, finally offsetting the dash by the length of the stroke. The magic happens when we apply our animation. We want the elements to draw one at a time, with some overlap between the end of drawing one element and beginning to draw the next. We start with completely straight vector lines, drawing each frame of our animation, depicting the bird in a different state of flight.
We then manipulate the vector points and round the lines and edges. Finally, we put each frame into an equally sized box and place them side-by-side. The first selector defines that at the start of the animation, the left margin of the div is 0px. The second selector defines that at the midway point of the animation cycle or at 2 seconds , the left margin is px.
The third selector defines that at the end of the animation or at 4 seconds, the margin is px. CSS animations are made up of two parts: keyframes and animation properties.
So to create a CSS animation, you have to define its keyframes and animation properties. Let's look at how below. The first part of a CSS animation is a set of keyframes. Since keyframes indicate the start and end of the animation, as well as any intermediate steps, they use percentages. These percentages indicate at which point in the animation sequence they take place. Say you want to style an element so it slides in from the right side of the browser window, like so. For this slide-in animation, there are just two keyframes.
We might, for example, add another keyframe so that the font size of the paragraph increases as it moves from right to left and then decreases back to its original size by the end of the sequence. With a firmer grasp of keyframes, we can now turn our attention to the second part that makes up CSS animations: animation properties.
These two properties are required for any animation to take effect. The animation-name property specifies the name of the keyframe. That's why in the examples above the value of the animation-name property — slidein — matched the name after keyframes. If you have multiple keyframes describing the animations to apply to an element, then you'll need to define multiple values for the animation-name property.
You can separate these with a space and comma. The animation-duration property specifies the length of time of the animation sequence. While the animation could play on loop forever, it should take however many seconds or milliseconds are specified in the animation-duration property to complete one cycle.
The property can be defined with zero or any positive value. Negative values are invalid. Below are some examples. In addition to the animation-name and animation-duration properties, there are other animation properties you can use to create more complex and custom animations. Let's define each below. The animation-timing function sets the pace of the animation. To specify the timing of your animation, you can use the predefined values ease , linear , ease-in , ease-out , and ease-in-out.
You can also create custom values using the cubic-bezier curve for more advanced timing options. If no other value is assigned, the function will be set at ease by default. Ease starts out slow, speeds up, then slows down. Below is an example.
Set at linear , the animation has the same speed from start to end. With ease-in , the animation has a slow start. With ease-out , it has a slow end. Ease-in-out means the animation has both a slow start and a slow end.
Using the animation-delay function , you can specify when the animation starts. Milliseconds and seconds are allowed, as are positive and negative values. A positive value will delay the animation sequence whereas a negative value will start the animation immediately, as if that amount of time has already gone by. If you set the value at 2s, for example, then the animation will start 2 seconds after it is loaded.
If you set the value at -2s, then the animation will start two seconds into the animation cycle. In the example below, a negative animation delay causes each circle to begin immediately at a different state in the animation cycle. The animation-iteration-count property specifies the number of times that the animation will play.
You can use a number value to have it repeat a certain number of times. You can set it to initial to use the default value 1 , which means the animation will play through its sequence once. You can set it to inherit to use the same value as its parent element. Or you can set it to infinite to have it repeat indefinitely. Take a look at the demo below which shows three versions of the same animation, each with their animation-iteration-count property set at different values. The animation-direction property defines the direction of the animation.
If you use the normal or default value, then the animation will play forwards. If you use reverse , it will play backwards. To have the animation reverse directions every cycle, you can use the alternate value the animation will play forwards first, then backwards or the alternate-reverse the animation will play backwards first, then forwards. Using the animation-fill-mode function , you can have the animation styles applied before or after the animation plays.
Below is an example of an animation with its animation-fill-mode property set to forwards and the default value normal. With the animation-play-state property, you can pause and resume the animation sequence.
By default, this property is set to running but you can set the property value to paused. Resuming a paused animation will play the animation from where it was paused, instead of starting over. Now that you have a better understanding of the different parts that make up an animation, you can create your own from scratch — or use a tool to help simplify the process. Using one will still require some familiarity with keyframes and animation properties — but it will reduce the complexity and require you to write less code.
Animista is a free application that allows you to customize pre-designed CSS animations. You can click on an animation type at the top of the screen this will be your animation name , then specify all the animation sub-properties in the left sidebar. Most are drop-down menus to make customizing your animation as easy as possible. When you're ready, you can click the Generate Code icon and paste it into your web pages or projects.
Similar to Animista, CSS Animations Generator allows you to customize the animation sub-properties for an animated element but not the keyframes.
When you're ready, you can copy the code for the animated element and keyframes at-rule and paste it into your web pages or projects. Designed to look and function like video-editing software, Keyframes is another free application that allows you to create basic or complex keyframe animations with a visual timeline editor. You can add "steps" using the timeline at the bottom of the screen and define different animatable properties in the right sidebar — these will be your keyframes.
You can also change the duration, iteration count, and other sub-properties at the bottom of the screen. Then when you're ready, you can click the Get CSS button and paste that code into your web pages or projects.
Ready to create CSS animations from scratch or with one of the generators above? In that case, you may run into some issues. Let's look at some ways to troubleshoot if your animations aren't working as you expect. The animation-duration property must also be set.
Animations are only executed when animation properties are applied, so they require explicit values for the properties being animated. These values are specified using keyframes.
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