Image Optimization Score Benchmarks by Industry

Image optimization score is a composite metric (0-100) that evaluates how well a site handles images across four dimensions: format efficiency (using modern formats like AVIF and WebP), compression level, responsive sizing (serving appropriately sized images for each viewport), and lazy loading implementation. Images typically account for 40-60% of total page weight, making image optimization one of the highest-leverage performance improvements.

Images and Page Performance

Unoptimized images directly degrade LCP (since the largest contentful element is often an image), increase total page weight, consume unnecessary bandwidth, and slow mobile load times. Despite this, image optimization remains one of the most neglected areas of web performance.

In 2026, AVIF format support has reached over 90% of global browser usage, making it the preferred format for photographic images with 50-70% smaller file sizes compared to JPEG. WebP remains a reliable fallback for the remaining browsers.

Industry Scores

E-commerce sites score a median of 55 out of 100. While product images are critical to conversion, many sites still serve oversized images, rely on legacy JPEG format, and lack proper responsive image implementations using srcset and sizes attributes.

SaaS sites perform better at 65 median. Fewer images per page and more technical teams contribute to better optimization, though hero images and screenshots are often served without modern format conversion.

Media sites score lowest at 50 median. The sheer volume of images — article thumbnails, hero images, embedded photos, and gallery pages — makes optimization at scale a significant challenge.

Healthcare sites score 48 median, with stock photography and medical imagery often uploaded directly from cameras without compression or format conversion.

Finance sites achieve 60 median, benefiting from image-light designs but still underperforming on the images they do use.

Optimizing Images Effectively

Implement an image optimization pipeline that automatically converts uploads to AVIF with WebP fallback, compresses to target quality levels (80-85% for photographic content), generates responsive sizes for common breakpoints, and applies lazy loading to below-the-fold images. Use <picture> elements with multiple sources for format negotiation, and always include explicit width and height attributes to prevent layout shifts.

Auditite scans every image on your site, scoring format efficiency, compression levels, responsive sizing implementation, and lazy loading coverage. It identifies the specific images with the largest optimization potential so you can prioritize changes that deliver the biggest performance gains.