Image optimization

Image optimization involves delivering images with the smallest possible file size while maintaining visual quality. Optimizing images means saving bytes and improving performance for your website: the fewer bytes per image, the faster the browser can download and render the content on your users’ screens. Research shows that this speed is directly related to visitor satisfaction and even monetary conversions.

For example, surveys performed by and Gomez reported statistics including:

  • Half of web users expect a website to load within two seconds.

  • A one-second delay in page load time can decrease visitor satisfaction by 16% and can also lead to a drop in conversion of 7% or more.

  • Load time is a major contributing factor to page abandonment, and the abandonment increases as a percentage with every second of load time, with nearly 40% of users abandoning a page after 3 seconds.

  • 73% of mobile internet users report that they’ve experienced problems with page load times on their devices.

These statistics are from 2009 and 2010, and it’s reasonable to assume that visitors’ expectations have only increased over time.

Most of the time, it is images, and in some cases videos, that have the most impact on slow load time. According to HTTP Archive, around 64% of a website’s average weight is images. Video accounts for another 9%.

Cloudinary’s built-in fast CDN delivery helps to get all resources to your users quickly. Additionally, Cloudinary automatically performs certain optimizations on all transformed images by default. But beyond this, Cloudinary also provides many features that enable you to further optimize images to fit your needs.

What is image optimization?

Optimizing an image involves delivering images in the format, dimensions, resolution, and quality that will yield the smallest possible file size while ensuring that the resulting image is appropriate for the specific content, the overall page design, the requesting device, and the expectations of your site visitors.

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Default optimizations

Whenever you apply any transformation to an image, Cloudinary performs the following optimizations by default:

  • Strips all associated metadata from the transformed image file (the original image is left untouched). To override this behavior and deliver a transformed image with its metadata intact, add the keep_iptc flag.

  • Applies an automatic quality adjustment to generated WebP, GIF, JPEG, and JPEG-XR formats. To override the default adjustments, set the quality parameter in your transformation.

  • Runs optimization algorithms to minimize the file size without impairing the visual quality when generating images in the PNG, JPEG or GIF format.


Web Developer with interest in Machine Learning.