Image Issues in PageSpeed Insights

Google PageSpeed Insights frequently flags image-related issues as opportunities to improve page performance. These issues can directly impact your Core Web Vitals scores and, by extension, your SEO rankings. This guide addresses each common image issue and how to fix it.

Issue 1: Serve Images in Next-Gen Formats

What it means: Your images are served as JPG or PNG when WEBP (or AVIF) would provide better compression at the same quality.

How to fix: Convert your images to WEBP using our WEBP Converter, then implement the <picture> element to serve WEBP with JPG/PNG fallback.

Issue 2: Efficiently Encode Images

What it means: Your images are not compressed enough and could be made smaller without visual quality loss.

How to fix: Run all images through our Image Compressor with quality set to 75-80%. Re-upload optimized versions to your server.

Issue 3: Properly Size Images

What it means: You're serving images much larger than their displayed size.

How to fix: Measure the maximum display size of each image (check CSS), then use our Image Resizer to resize images to that exact dimension before uploading.

Issue 4: Defer Offscreen Images

What it means: Images below the fold are being loaded before they're needed.

How to fix: Add loading="lazy" to all images that are not in the initial viewport.

Issue 5: Image Elements Do Not Have Explicit Width and Height

What it means: Images without explicit dimensions cause layout shifts (CLS) as they load.

How to fix: Always add width and height attributes to <img> elements matching the image's natural dimensions.

Workflow for Zero Image Warnings

  1. Audit with PageSpeed Insights to identify which images are flagged
  2. Resize images to maximum display size using our Resizer
  3. Compress using our Compressor
  4. Convert to WEBP using our WEBP Converter
  5. Update HTML with correct width/height and loading="lazy"
  6. Re-run PageSpeed Insights to verify improvements

Conclusion

Fixing PageSpeed Insights image issues is one of the highest-ROI performance improvements you can make. Use ImageToolHub's free tools to address every image-related warning and significantly improve your scores.