**Course Title:** Modern CSS: Responsive Design and Advanced Techniques **Section Title:** Transitions, Animations, and Transforms **Topic:** Best practices for creating smooth and performant animations Creating smooth and performant animations is crucial in modern web development as it directly impacts the user experience. In this topic, we'll discuss the best practices for creating animations that not only run smoothly but also don't compromise the performance of your website. ### Understanding Performance in CSS Animations Before we dive into the best practices, it's essential to understand what affects the performance of CSS animations. Animations that involve changes to the following properties are more expensive in terms of performance: 1. **Layout properties**: `width`, `height`, `top`, `left`, `right`, `bottom`, `padding`, `margin`, `border`, `position`, `display`, `float`, `clear`, `vertical-align`, `overflow`, `overflow-x`, `overflow-y` 2. **Paint properties**: `color`, `background-image`, `background-position`, `background-size`, `background-repeat`, `outline-color`, `outline-style`, `outline-width`, `box-shadow`, `text-shadow` 3. **Composite properties**: `opacity`, `transform`, `filter`, `backdrop-filter` On the other hand, changes to properties like `transform`, `opacity`, and `filter` are generally inexpensive and won't significantly impact performance. ### Best Practices for Creating Smooth Animations 1. **Use the GPU**: Using the GPU (Graphics Processing Unit) can significantly improve the performance of animations. You can use the `transform` property to activate the GPU. Prefix the `transform` property with `-webkit-` or `-moz-` if you need to support older browsers. ```css .example { transform: translateZ(0); } ``` This will force the browser to use the GPU, resulting in smoother animations. 2. **Use Will-change**: The `will-change` property is a hint to the browser about the properties that will change during an animation. This property allows the browser to optimize the animation beforehand. ```css .example { will-change: transform; } ``` By setting `will-change` to `transform`, we're telling the browser that this property will change during the animation. 3. **Use requestAnimationFrame**: `requestAnimationFrame` is a function that allows you to execute a function before the next repaint of the screen. This ensures that your animation runs smoothly and doesn't miss any frames. ```javascript function animate() { // Your animation code here requestAnimationFrame(animate); } animate(); ``` In this example, the `animate` function will be called before the next repaint of the screen. 4. **Avoid Using JavaScript Animations**: While JavaScript animations can be powerful, they can also be resource-intensive and slower than CSS animations. Whenever possible, use CSS animations instead of JavaScript. 5. **Optimize CSS Animations**: Use CSS animations with caution. While they can be powerful, they can also cause performance issues if not optimized properly. ```css .example { animation: spin 1s linear infinite; } @keyframes spin { to { transform: rotate(360deg); } } ``` In this example, we're animating the `transform` property, which is a relatively inexpensive animation. ### Best Practices for Creating Performant Animations 1. **Avoid Animating Expensive Properties**: As mentioned earlier, properties like `width`, `height`, `top`, `left`, `right`, `bottom`, `padding`, `margin`, `border`, `position`, `display`, `float`, `clear`, `vertical-align`, `overflow`, `overflow-x`, `overflow-y` can be expensive to animate. Try to avoid animating these properties whenever possible. 2. **Use CSS Animations Instead of Transitions**: CSS animations are generally more performant than transitions. This is because animations can be optimized by the browser beforehand. ```css .example { animation: spin 1s linear infinite; } @keyframes spin { to { transform: rotate(360deg); } } ``` In this example, we're using a CSS animation instead of a transition. 3. **Avoid Over-animating**: Animations should enhance the user experience, not overwhelm it. Avoid over-animating your website, as this can cause performance issues and distract the user. ### Conclusion Creating smooth and performant animations requires careful consideration of the properties being animated and the techniques used to animate them. By following the best practices outlined in this topic, you can create animations that not only run smoothly but also don't compromise the performance of your website. If you have any questions or need help with animations, feel free to comment below. In the next topic, we'll be covering **Introduction to CSS variables and how they improve maintainability**. This topic will cover the basics of CSS variables, including how to declare and use them, and how they can improve the maintainability of your CSS code. [Continue to the next topic](/css-variables-and-maintainability). External Resources: * [CSS performance optimization techniques](https://web.dev/fast/): A comprehensive guide to optimizing CSS performance by Google. * [The Cost of JavaScript](https://medium.com/@addyosmani/the-cost-of-javascript-84009f15140d): An article by Addy Osmani on the cost of JavaScript and how to optimize it. * [Optimizing CSS animations](https://medium.com/@bretcameron/optimizing-css-animations-5b2fe89970a9): An article by Bret Cameron on optimizing CSS animations.