Optimize image sizes, formats, and lazy loading behavior.
- Optimize image sizes, formats, and lazy loading behavior3 cited sources2 categories
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Why this matters
Properly optimized images reduce page load times, improve mobile usability, and support Core Web Vitals.
Hypothetical standard operating procedure
Adapt this example to your site, access, tools, and change process. It is our suggested procedure, informed by the sources below.
- Review current images on critical pages for size and format using audit tools.
- Convert images to modern formats where supported and compress without losing quality.
- Configure lazy loading with loading="lazy" attribute on images below the fold.
- Set explicit width and height to prevent layout shifts.
- Test pages to confirm images load quickly and appear sharp on all devices.
Watch for
Oversized or uncompressed images increase load times and trigger poor LCP scores.
Definition of done
Images are correctly sized, compressed, use modern formats like WebP or AVIF, and offscreen images lazy-load.
Sources & attribution
Original checklist wording and example SOP by Best SEO Checklist, using source-grounded AI assistance. Editorial contact: Ted Kubaitis, @tedkubaitis on Teams. Check current source guidance before implementation.