Free Speed & UX tool
Image Optimization Checker
Find images that are too big, in old formats or loaded at the wrong time, and how much faster the page gets when you fix them.
- Free
- No sign-up
- Real Chrome, about 30 seconds
What it checks
Modern formats
JPEG and PNG files that would be much smaller as WebP or AVIF.
Right size
Images served far bigger than they’re shown on screen.
Compression
Images that could lose weight with no visible change.
Lazy loading
Off-screen images that load before anyone scrolls to them.
The LCP image
Whether the main image is prioritised or held back.
Page weight
How much of the page’s total download is images.
Questions
Which image format should I use?
AVIF is smallest, WebP is close behind and works everywhere. Most image CDNs and frameworks can serve them automatically, with JPEG as a fallback.
Should I lazy-load every image?
No. Lazy-load images below the fold, but never the main image at the top. Give that one fetchpriority="high" so it loads first.
How much can image optimization save?
Often half the page weight or more. Each issue in the report shows the bytes and time you would save.