How Can Leveraging Modern Image Formats, as Recommended by PageSpeed Insights, Enhance Site Speed and Overall SEO Performance?


Leveraging modern image formats such as WebP and AVIF, as recommended by PageSpeed Insights, can significantly enhance site speed and overall SEO performance. These formats offer superior compression and quality metrics compared to traditional formats like JPEG and PNG, leading to faster load times and improved user experience, which are critical factors for search engine optimization.

Modern Image Formats


WebP is an image format developed by Google that provides superior lossless and lossy compression for images on the web. WebP images are smaller in size than their JPEG or PNG counterparts, which results in faster loading times.

  • WebP supports both lossy and lossless compression, allowing web developers to choose the best balance of quality and file size for their needs. [WebP, 2023]
  • According to Google, WebP lossless images are 26% smaller in size compared to PNGs, and WebP lossy images are 25-34% smaller compared to JPEGs. [WebP Compression Study, 2023]


AVIF (AV1 Image File Format) is another modern image format that provides even better compression rates than WebP. It supports high dynamic range (HDR) and offers impressive image quality at smaller file sizes.

  • AVIF images are up to 50% smaller in size compared to JPEG without significant loss in quality. [AVIF, 2023]
  • This format is supported by all major browsers, including Chrome, Firefox, and Safari, making it a practical choice for web developers. [Can I Use AVIF?, 2023]

Impact on Site Speed

Reduced Load Times

Smaller image file sizes mean that they take less time to download, leading to faster page load times. This is crucial because faster loading times improve user experience and reduce bounce rates.

  • Studies indicate that a 1-second delay in page load time can lead to a 7% reduction in conversions, reinforcing the importance of fast-loading images. [Akamai Performance Study, 2023]
  • Google's PageSpeed Insights provides recommendations to use WebP and AVIF to improve page speed scores. [PageSpeed Insights, 2023]

Improved Core Web Vitals

Core Web Vitals are a set of metrics by Google that measure the real-world user experience of a webpage. Utilizing modern image formats can positively impact these metrics:

  • Largest Contentful Paint (LCP): Faster loading times for the largest image element on the page enhance LCP scores. [Largest Contentful Paint, 2023]
  • First Input Delay (FID): Although FID is more about interactivity, faster image loading indirectly helps improve overall user experience. [First Input Delay, 2023]
  • Cumulative Layout Shift (CLS): By using smaller images, there is less likelihood of shifts in layout, improving CLS scores. [Cumulative Layout Shift, 2023]

SEO Performance

Better Rankings

Google favors websites that provide better user experiences, including faster load times. By using modern image formats, the overall website performance is improved, which can contribute to higher search engine rankings.

User Engagement

Faster pages lead to greater user satisfaction and engagement, including more time spent on the site and higher conversion rates.