Images are the main culprit for causing large web pages that can perform slowly on mobile devices. That puts you at risk of visitors moving on before they have seen anything (we are all so impatient!) and will hurt your SEO for your mobile site.
There are several ways to reduce the impact of images on the performance of your website.
Remove unnecessary images.
The easiest way to improve page speed is to remove unnecessary images. If images do not add value get rid of them. Look for opportunities to use a button or other visual element to get visitors’ attention.
Size images correctly.
Modern CMS systems allow you to upload huge images and display them at the proper sizes. Make sure that you upload images that are no larger than the largest size needed at your site. All the rest of those pixels will just slow you down.
Make images work hard.
Make sure every image you present on mobile adds to the message and the story you want to tell. Part of making images work is ensuring that each one has a meaningful, keyword-relevant alt tag.