CSS animations and transitions can add visual flair and interactivity to your web design, but they can also affect user experience if not used wisely. In this article, we will share some CSS best practices to help you implement animations and transitions that enhance your web design without compromising performance, accessibility, or usability.
Before you start adding animations and transitions to your web design, you should understand the difference between them. CSS animations are defined by the @keyframes rule, which specifies the changes in the properties of an element over time. CSS transitions are defined by the transition property, which specifies the duration and easing of the change in one or more properties of an element when a state change occurs. Animations are more complex and flexible, but transitions are simpler and smoother.
One of the most important CSS best practices for animations and transitions is to use the transform property whenever possible. The transform property allows you to move, rotate, scale, or skew an element without affecting the layout or flow of the document. This means that the browser does not have to repaint or reflow the element, which improves performance and reduces jank. The transform property also enables hardware acceleration, which uses the GPU to render the animation or transition faster and smoother.
Using transform as a hover effect that shortens or elongates the button notifies the user of an interactive element on the site without affecting the readability of a button. Small details that help communicate with the end user builds trust.
Another CSS best practice for animations and transitions is to avoid animating layout properties, such as width, height, margin, padding, or position. These properties affect the layout and flow of the document, which means that the browser has to repaint and reflow the element and its surrounding elements every time the animation or transition runs. This can cause performance issues and jank, especially on mobile devices or low-end machines. Instead, try to use the transform property or other properties that do not affect the layout, such as opacity, color, or filter.
The will-change property is a CSS feature that allows you to inform the browser that an element is likely to change in the future, such as when an animation or transition is triggered. This allows the browser to optimize the rendering of the element and its children, such as creating a separate layer, applying hardware acceleration, or pre-computing the changes. The will-change property can improve the performance and smoothness of your animations and transitions, but it should be used sparingly and only when necessary, as it can also consume more memory and resources.
The last CSS best practice for animations and transitions is to consider the accessibility and usability of your web design. Animations and transitions can create visually appealing effects, but they can also cause problems for some users. To avoid causing discomfort or distraction, you should provide an option to disable or reduce animations and transitions, such as using the prefers-reduced-motion media query or a toggle button. Additionally, you should avoid animations or transitions that are too fast, too slow, too frequent, or too complex. It is also important to use animations or transitions that are meaningful and relevant, not just decorative or arbitrary, as they can help convey information, feedback, or context. Finally, you should test your animations or transitions on different devices, browsers, and screen sizes to ensure they do not affect the functionality, readability, or responsiveness of your web design.