The Opportunities section of your Lighthouse report lists all animated GIFs, along with estimated savings in seconds achieved by converting these GIFs to video:
See the Lighthouse performance scoring post to learn how your page's overall performance score is calculated.
Why you should replace animated GIFs with video #
Large GIFs are inefficient for delivering animated content. By converting large GIFs to videos, you can save big on users' bandwidth. Consider using MPEG4/WebM videos for animations and PNG/WebP for static images instead of GIF to save network bytes.
Create MPEG videos #
There are a number of ways to convert GIFs to video. FFmpeg is the tool used in this guide. To use FFmpeg to convert the GIF,
my-animation.gif to an MP4 video, run the following command in your console:
ffmpeg -i my-animation.gif my-animation.mp4
This tells FFmpeg to take
my-animation.gif as the input, signified by the
-i flag, and to convert it to a video called
Create WebM videos #
WebM videos are much smaller than MP4 videos, but not all browsers support WebM so it makes sense to generate both.
To use FFmpeg to convert
my-animation.gif to a WebM video, run the following command in your console:
ffmpeg -i my-animation.gif -c vp9 -b:v 0 -crf 41 my-animation.webm
Replace the GIF image with a video #
Animated GIFs have three key traits that a video needs to replicate:
- They play automatically.
- They loop continuously (usually, but it is possible to prevent looping).
- They're silent.
Luckily, you can recreate these behaviors using the
<video autoplay loop muted playsinline>
<source src="my-animation.webm" type="video/webm">
<source src="my-animation.mp4" type="video/mp4">
Use a service that converts GIFs to HTML5 videos #
Many image CDNs support GIF to HTML5 video conversion. You upload a GIF to the image CDN, and the image CDN returns an HTML5 video.
Stack-specific guidance #
For animated content, use
amp-anim to minimize CPU usage when the content is offscreen.