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Low Modern Image Format Adoption (WebP / AVIF)

No images use modern formats like WebP or AVIF; all detected images are legacy JPEG/PNG formats.

By Seoxpert Editorial · Published

Why it matters

Modern image formats like WebP and AVIF significantly reduce file sizes compared to JPEG and PNG, improving page load speed and Core Web Vitals (LCP). Faster image delivery enhances user experience and can positively impact SEO rankings.

Impact

Failing to use modern image formats leads to slower page loads and potential negative effects on SEO and user engagement.

How it's detected

An automated crawler scans image URLs and MIME types, flagging sites where images are not served in WebP or AVIF formats.

Common causes

  • •Images uploaded only in JPEG or PNG formats
  • •Lack of automated image optimization pipeline
  • •CMS or hosting platform does not support modern formats
  • •Developers unaware of browser support for WebP/AVIF
  • •No use of <picture> element for format fallback

How to fix it

Convert images to WebP or AVIF using image processing tools or services. Update your image delivery pipeline (e.g., Next.js Image, Cloudinary) to auto-serve modern formats with legacy fallbacks. For manual control, use the <picture> element with <source> tags for AVIF and WebP, and an <img> fallback for older browsers.

Code examples

Legacy image format (problem)

<img src="photo.jpg" alt="Sample photo">

Modern formats with fallback (solution)

<picture>
  <source srcset="photo.avif" type="image/avif">
  <source srcset="photo.webp" type="image/webp">
  <img src="photo.jpg" alt="Sample photo">
</picture>

FAQ

How do I convert existing JPEG or PNG images to WebP or AVIF?

You can use tools like ImageMagick, Squoosh, or online converters to generate WebP or AVIF versions of your images.

Will using WebP or AVIF break image loading in older browsers?

No, if you use the <picture> element with a fallback <img> tag, older browsers will load the JPEG or PNG version.

Does my CMS or image CDN support automatic WebP/AVIF delivery?

Many modern CMS and CDNs offer automatic conversion and delivery of images in modern formats; check your provider's documentation.

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