3.1 Images with embedded text are avoided
Images with embedded text are hard for Google and screen readers to read, and they can’t be easily updated when you update your brand standards.
3.2 Images are appropriately sized and not too large
Excessively-large images as a major cause of slow websites. Make sure images are the right size for where they’ll be displayed.
3.3 Images are compressed
Run images through image optimization software if possible. Many CMSes also have plugins to do this for you automatically.
3.4 Alt tags containing keywords are used for images
Alt tags make your images easier to understand, and help ensure you’re using images that are relevant to your message.
3.5 Images are captioned or otherwise referred to in text
Explanations or references to images make it easier for search engines – and your users – to understand why they’re there and how to interpret them.
3.6 Images do not "lazy load"
Lazy loading – where an image is loaded when it scrolls into view for the user – in most cases just means that a user has to wait for your image to load, especially given that many users scroll quickly. Instead of using this strategy to save bandwidth, ensure that images are appropriately sized and compressed.
3.7 Images and other resources have descriptive filenames
Descriptive filenames are useful for all content marketers in managing image libraries, and they provide another way for users and search engines to understand what the image is about.
3.8 Generic stock photos are avoided
Generic stock photos usually don’t add meaning or value to your content and are, as a result, good to avoid. They also can indicate other problems with your content processes, which we talk about more in our 5-minute SEO audit. If you’re using a decorative or background image, ideally it should be incorporated as part of your CSS rather than within the HTML.
3.9 Illustrations, diagrams and real photos are used if possible
Illustrations and diagrams add value to your content and should be used whenever possible and appropriate. Real photos – for example, of customers or people on your team – can engage users and help them make a connection to your company.