Why are broken CSS images important?
If the style sheet contains outdated links to images, it's possible that these images have been removed from the server in the meantime. If the web browser of the online visitor still tries to load these links, it can result in the visitor seeing broken images on the website. This in turn causes an unpleasant user experience. Another consequence of the images not being found is the increased contamination of the 404 not found logs in the web server.
One way of detecting broken images in a style sheet is by manually checking it, running through all the images to make sure they're still located on the server. Another way of detecting broken images is by checking the 404 server logs to see whether any images have recently not been found.
Keeping the style sheet clean and free of broken images is an important part of ensuring a smooth and seamless user experience and helps to create a clear overview of the webmaster's maintenance tasks.