Accessibility Jumpstart 2: Standards

Posted on Category: Accessibility
Carp and fly (1900 - 1930) by Ohara Koson (1877-1945). Original from The Rijksmuseum. Digitally enhanced by rawpixel.

Greetings, and welcome to part 2 of a series to help jumpstart your understanding of web accessibility. If you haven’t read part 1 yet, we covered what web accessibility is and addressed some of the misconceptions around it. This time we will be providing a brief overview of the standards governing web accessibility globally.

What’s a WCAG?

The Web Content Accessibility Guidelines (or WCAG for short, often pronounced “wi-kag” or “wuh-kag”), were first published in 1999. At the time of writing WCAG is on version 2.1, with 2.2 in working draft. It was devised and published by the committee that mandates web standards called the World Wide Web Consortium, or W3C for short.

Additionally, WCAG 2.0 itself is approved as an ISO standard (ISO/IEC 40500:2012) by the International Organization of Standards. If you’re interested in a more complete history, check out the Wikipedia page.

What does WCAG cover?

While we won’t be covering all of WCAG here, it’s important to be aware of its goals and limitations. WCAG mandates that all web content should be Perceivable, Operable, Understandable, Robust (or POUR for short). It heavily targets people with visual, auditory, and motor disabilities. It also covers some needs related to cognitive issues, photosensitive epilepsy, and those with vestibular disorders.

Today, WCAG evaluates compliance at 3 different levels. A, AA, and AAA. Standards with the “Level A” rating are the bare minimum web apps should adhere to. A “Level AA” rating is the standard level of accessibility that websites and web apps should adhere to. It also is what almost every country uses as the standard to measure accessibility support. Finally, the “Level AAA” are gold-level standards. They are often unused as they are typically for unique situations such as live voice transcription etc. In terms of support levels, anything that meets AAA will also meet AA, and so on. In WCAG 2.1 there are 30 “Level A” standards, 20 “Level AA” standards, and 28 “Level AAA” standards. In total, there are 78 unique standards, 50 of which encompass A and AA support, the requirement for most governments around the world.

In terms of the standards themselves, around 39 or so item deal with providing information to Assistive Technologies (AT, more on that in a future article) directly, the remainder are about general usability. In terms of the disabilities targeted in WCAG 2.1 there are around…

  • 47 that cover many needs or provide content to Assistive tech (AT) directly for programatic interpretation
  • 18 that target visual challenges (blind, low vision, color blind, photosensitivity, vestibular, etc.)
  • 10 that target auditory challenges (deaf, hard of hearing, etc.)
  • 5 that target motor challenges (paralysis, Parkinson’s disease, MS, arthritis, etc.)
  • 4 that target cognitive challenges (dyslexia, autistic spectrum, etc.)

If you are looking for a nice overview of each standard in common language, check out Luke McGrath’s resources over at wuchag. If you’d like to see the breakdown of the metrics listed above, check out the spreadsheet the math was done in.

The future of WCAG

While WCAG 2.1 is the current recommendation, WCAG version 2.2 is coming pretty soon and is currently in working draft mode. WCAG 2.2 will cover all the old standards, plus add a few new ones that cover authentication, dragging, more focus guidelines, control usage and placement, and some new guidance on help content.

If that’s not enough, there is a full overhaul coming to WCAG (WCAG 3, previously codenamed “Silver”), which essentially changes how accessibility is measured and what it’s applied to on the web. For a far better explanation that I can give, check out Level Access’s webinar on WCAG 3.0.

Addendum: W3C just pushed out the first draft of WCAG 3!

Other standards to be aware of

Finally, there are a few other international standards that you should be aware of. While these standards are not “law” in most countries, there are companies that will require them to be followed.

  • ATAG 2.0 (Authoring Tool Accessibility Guidelines) – Additional guidelines for web applications that are also authoring platforms. Essentially tries to prevent authors from creating poor accessible experiences, and guide the authoring system itself to also be accessible.
  • PDF/A – International standards for PDF accessibility. Evaluated differently than WCAG or ATAG.
  • EPUB accessibility 1.0 – eBook standards also organized by the W3C. Expects one-to-one compliance with WCAG 2.0 AA, along with a few eBook-specific improvements.
  • ANSI/HFES 200.2 – An ISO standard (ISO 9241-171:2008), human factors accessibility standards for software (not web apps). This may apply however to Electron-like applications. View a free version of the standard here. Evaluated differently than WCAG or ATAG.


In order to meet accessibility standards well, it will be important to have both designers and developers that are intimately familiar with WCAG 2.1 AA. In the next part of the series, we will be discussing the legal landscape and how these standards may affect your business or startup.

Want to read the rest of the series?

  1. What Is Accessibility?
  2. Standards
  3. The Law
  4. Assistive Technology
  5. Using Assistive Technology
  6. User Testing
  7. Dev & Design Tools
  8. Staying Current with Accessibility
My opinions & views expressed may not reflect my employer's.