Image Optimization Test FAQ

The most frequently asked questions
What does this tool do? This tool analyzes whether the images loaded on a page are optimally delivered and optimized when it comes to page speed. It checks whether:
  • The images are optimally minified (to save disk space).
  • The image dimensions (width and height) are set (for quicker page rendering).
  • Images are found which could be used in a CSS sprite.
  • Duplicate images are found.
  • The favicon of the website is optimally compressed and cached.
Why is image delivery & optimization important for speed? Perfecting the image delivery and optimization can make a huge difference in page speed especially if there are many images/photos on a page. Compressing images can save a lot of disk space which can in turn speed up page load times. Using a CSS sprite to display multiple images at once with one image request will result in fewer http requests. Pre-setting the dimensions of images with CSS or HTML will result in quicker rendering of the page.