As libraries continue to grow as hubs of knowledge and information sharing on campuses and in communities, the importance of web accessibility measures ensuring fair, equivalent access has risen in visibility. Advanced best practices for making a variety of interfaces usable and understandable for a wide selection of assistive technologies will be detailed, including code samples and use cases. This talk will also outline how to conduct accessibility testing during agile development, including footage from an actual web accessibility test of an interface in development. Operating with the knowledge that we as a community understand why web accessibility is important and are in agreement on the need for baseline accessibility measures, this talk will put advanced tools in the hands of all library professionals to continuously improve their own applications, and also work toward and advocate for better accessibility measures in all areas of Libraries, from their own Libraries website to vendor solutions and beyond.