In terms of digital accessibility, automated tools can't check for every accessibility issue. It is important to follow up with a manual review for a more complete picture. This can be done by reviewing websites with accessibility best practices in mind, like testing a page while just using your keyboard to navigate or listening to the page with a screen reader. These are things that developers can manually test on their own while they are putting content online.
The internet is the world's most significant public space today. Yet, 97% of it is inaccessible to people with disabilities.
In 1995, Microsoft began building accessibility into its operating system. This allowed users and developers to test content more easily. In 1998, Section 508 of the US Rehabilitation Act of 1973 was expanded to require that all federal agencies make their websites accessible to people with disabilities.