Avoiding Non-Composited Animations in WordPress

Avoid non-composited animations is performance metric that highlights the need to optimize animations to be handled by the browser’s compositor thread instead of the main thread. This is particularly relevant in the context of complex web applications like WordPress sites, where interactive elements and animations can enhance user experience if implemented efficiently.

Impact on WordPress Performance

Animations that are not composited can force the main thread to do the heavy lifting of painting and layer composition, which are resource-intensive tasks. This can lead to several performance issues:

• Decreased Frame Rate: Non-composited animations can cause frame rates to drop, leading to choppy and laggy animations that degrade the user experience.
• Increased Load on Main Thread: Handling these animations on the main thread can delay processing other critical tasks such as responding to user inputs or loading essential page elements.
• Extended Time to Interactive (TTI): The more work the main thread has to do, the longer it takes for a page to become fully interactive, potentially increasing bounce rates.

How to Resolve Non-Composited Animations

1. Use CSS Properties that are GPU-accelerated:
   • Stick to animating properties like opacity and transform. These can often be handled by the GPU, which helps in keeping the animations smooth and off the main thread.
2. Optimize and Test with DevTools:
   • Use Chrome’s DevTools to identify and eliminate non-composited animations. The “Layers” and “Performance” panels can help you understand how your animations are being rendered and optimized.
3. Limit Complex Animations:
   • Simplify animations to reduce their performance impact, especially on mobile devices where computational resources are more limited.
   • Consider whether an animation is essential from a user experience perspective and remove or redesign overly complex animations that contribute little to functionality or aesthetic value.
4. Use Web Animation API:
   • For more complex animations, consider using the Web Animations API, which provides more control over animation performance and can help offload some of the work to the browser’s optimization mechanisms.
5. Implement requestAnimationFrame for JavaScript Animations:
   • If you need to use JavaScript to control animations, make sure to use requestAnimationFrame instead of setTimeout or setInterval. This method allows the browser to optimize animation rendering, syncing frames smoothly.
6. Avoid Animating Layout Properties:
   • Avoid animating properties that trigger layout changes (like width, height, left, top, etc.) as they require recalculating element positions and geometries, which is costly.
7. Prefer CSS Transitions and Animations:
   • Whenever possible, use CSS transitions and animations instead of JavaScript animations. CSS is generally more performance-friendly for animations because it allows the browser to optimize performance under the hood.

By focusing on these strategies, you can improve the performance of animations on your WordPress site, ensuring they enhance rather than detract from the user experience. Well-optimized animations not only look smoother but also contribute to a faster, more responsive site.