Images
Image dimensions declared
Images declare width and height to prevent layout shift
What we check
Images declare width and height to prevent layout shift
Why it matters
Undeclared dimensions cause the page to jump as images load.
How to fix it
Add width and height attributes to every img element.
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.