Pass Google PageSpeed Image Audits: A Step-by-Step Fix

Google PageSpeed Insights routinely flags two image-related issues: "Serve images in next-gen formats" and "Properly size images." Together, these are often the biggest opportunities for improving your performance score. Here's how to fix both.

Audit 1: "Serve images in next-gen formats"

This audit fires when you're serving JPEG or PNG images that could be WebP or AVIF.

The fix

1. Open the Compress & Convert tool
2. Drop each flagged image
3. Convert to WebP (quality 75-80) or AVIF (quality 65-75)
4. Replace the original file on your server
5. Update your HTML if the file extension changed

Expected savings

WebP: 25-35% smaller than JPEG. AVIF: 50-70% smaller than JPEG. For a page with 2MB of JPEG images, WebP saves 500-700KB and AVIF saves 1-1.4MB.

Audit 2: "Properly size images"

This audit fires when images are significantly larger than their display dimensions. A 4000px-wide image displayed at 800px wastes bandwidth.

The fix

1. Check the display size in the PageSpeed report (it tells you the optimal dimensions)
2. Open the Resize tool
3. Set width to the recommended dimension (multiply by 2 for retina)
4. Replace the oversized image on your server

Expected savings

Resizing a 4000px image to 1600px (800px display x 2x retina) typically reduces file size by 75-85% before any compression is applied.

The Combined Workflow

1. Resize to the optimal dimensions (2x display size)
2. Convert to WebP quality 80 (or AVIF with WebP fallback)
3. Strip metadata to save an additional 10-50KB per image
4. Upload and replace

Measuring the Impact

After replacing images, re-run PageSpeed Insights. You should see:

• Image audits passing (green)
• LCP improvement (faster largest content paint)
• Overall Performance score increase (often 5-20 points from images alone)

Conclusion

Fixing image-related PageSpeed audits is the highest-impact performance optimization for most websites. The resize-convert-strip workflow using COMBb2's tools takes about 1 minute per image and can improve your PageSpeed score by 5-20 points. All processing happens in your browser - no images sent to optimization services.