Images
Modern image formats
Images use WebP or AVIF where supported
What we check
Images use WebP or AVIF where supported
Why it matters
Modern formats are typically 30% smaller at the same quality.
How to fix it
Convert JPEG and PNG assets to WebP or AVIF.
How it affects your score
This check sits in Images, which is worth 10% of the overall score. A critical result costs the full weight of the check; a warning costs half. If we can't measure it on your page, we leave it out of the score entirely.