The Essentials
One commercial tool, one free tool, one free document – these are the bare essential PDF resources for 508 remediation.
- Adobe Acrobat Professional
- PDF Accessibility Checker (PAC 3) from the Swiss Foundation Access for All, provides PDF/UA testing – to the extent that testing can be automated – and a screen-reader-emulator to display a PDF in the way that an assistive technology user would hear it.
- The Matterhorn Protocol, from the PDF Association’s PDF/UA Technical Working Group, provides PDF/UA compliance criteria. It includes checkpoints that can be automated as well as those that require human inspection.
Advanced Commercial Tools
If you invest in one or both or these tool sets, you will likely find much less need to visit the 508 PDF Help Center. These tools automate many PDF accessibility remediation tasks.
Helpful Free Tools
- PAC 1.3 (scroll to the bottom of the page): The predecessor of PAC 2, PAC 1.3 has a different style of screen-reader-emulator that I prefer, especially when working with tables.
- CommonLook PDF Validator from NetCentric Technologies checks a PDF against Section 508, WCAG 2.0 AA, PDF/UA, and HHS (U.S. Health and Human Services) standards, as well as checking other factors such as broken links.
- pdfGoHTML from Callas Software provides a screen-reader-emulator view somewhat similar to the viewer in PAC 2, with some additional features. pdfGoHTML installs as an Acrobat Pro plug in, making it very convenient to use while working in Acrobat Pro.
- VIP PDF Reader from the Swiss National Association of and for the Blind is another great tool for visually checking the reading order and certain other human-inspection-needed PDF accessibility factors.
- Colour Contrast Analyser from The Paciello Group is a simple tool for checking luminosity contrast, for example to help determine the legibility of colored text on a shaded background.
Helpful Free Documents and Websites
- Adobe’s version of ISO 32000-1: The official version of ISO 32000 – the standard that defines the Portable Document Format – can be purchased from the International Organization for Standardization, but there is no need. The free version from Adobe has the same content and even the same page and section numbers.
- The PDF/UA Reference Suite: The PDF Association’s PDF/UA Technical Working Group publishes this set of ten PDF/UA compliant documents as a reference for best-practices for creating accessible tagged PDF files.
- Adobe’s Create and verify PDF accessibility (Acrobat Pro)
Document Available for Purchase
- ISO 14289-1:2014 (PDF/UA) is the authoritative worldwide standard for PDF universal accessibility.

