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Jim Byrne Accessible Website Design Glasgow for The Third Sector, Voluntary, Charities and Not for Profits

Accessible, Responsive Website Design
Jim Byrne Web Designer

WCAG 2.1 Guidelines Explained

A history lesson: where did the website accessibility guidelines come from and what’s in them?

  • 1995: The first web accessibility guidelines were compiled by Gregg Vanderheiden shortly after the 1995 Chicago WWW II Conference.
  • 1998: University of Wisconsin–Madison compiled the Unified Web Site Accessibility Guidelines.
  • 1999: they formed the basis for WCAG 1.0.

WCAG 1.0. were focused on HTML and web pages.

  • 14 guidelines.
  • 65 checkpoints.
  • Each with a priority level: A, AA. AAA.

A Compliance: the guidelines must be satisfied otherwise it will be impossible for one or more groups to access the Web content.

AA Compliance: should be satisfied, otherwise some groups will find it difficult to access the Web content.

AAA Compliance: may be satisfied: to make it easier for some groups to access the Web content.

14 WCAG 1 Guidelines

  • Guideline 1: Provide equivalent alternatives to auditory and visual content.
  • Guideline 2: Don’t rely on colour alone.
  • Guideline 3: Use markup and style sheets, and do so properly.
  • Guideline 4: Clarify natural language usage.
  • Guideline 5: Create tables that transform gracefully.
  • Guideline 6: Ensure that pages featuring new technologies transform gracefully.
  • Guideline 7: Ensure user control of time-sensitive content changes.
  • Guideline 8: Ensure direct accessibility of embedded user interfaces.
  • Guideline 9: Design for device independence.
  • Guideline 10: Use interim solutions.
  • Guideline 11: Use W3C technologies and guidelines.
  • Guideline 12: Provide context and orientation information.
  • Guideline 13: Provide clear navigation mechanisms.
  • Guideline 14: Ensure that documents are clear and simple.

WCAG 2 – Published 2008

Not just websites, but also PDF, Google Docs, Spreadsheets, e-Books… and other ‘digital assets’.

WCAG 2.1 – Published 2018

  • WCAG 2.1 does not deprecate or supersede WCAG 2.0.
  • The differences between WCAG 2.0 and 2.1 are mostly related to the use of tablets and mobile devices.
  • They are designed to make content more accessible to a wider range of people, including accommodations for blindness and low vision.

WCAG 2.1 Based on 4 Principles

  • Perceivable.
  • Operable.
  • Understandable.
  • Robust

What principles?

  • Perceivable?
  • Operable?
  • Understandable?
  • Robust?

What do the principles mean?


WCAG speak: information and user interface components must be presentable to users in ways they can perceive.

Jim speak: the site visitor must be able to recognise that the content exists. For example, by being able to see it, hear it or touch it.


  • WCAG speak: user interface components and navigation must be operable.
  • Jim speak: the site visitor must be able to navigate around the site and use the features and functions presented.


  • WCAG speak: information and the operation of user interfaces must be understandable.
  • Jim speak: not only should visitors be able to recognise the existence of the content and be able to interact with it, but they must also be able to understand it.


  • WCAG speak: content must be robust enough that it can be interpreted reliably by a wide variety of user agents, including assistive technologies.
  • Jim speak: it must be possible to access the content using everything from a text-only web browser to the latest Firefox browser. And everything in between, including screen readers and all the different brands and versions of browsers now available.

Each Principle Has A Set Of Guidelines

1. Perceivable: the guidelines relate to:

  • Text alternatives for non-text content.
  • Captions and other alternatives for multimedia.
  • Content can be presented in different ways, including by assistive technologies, without losing meaning.

Operable: the guideline Relate To:

  • Ensuring functionality is available for keyboard users.
  • Giving users enough time to read and use content.
  • Avoiding content that causes seizures or physical reactions.
  • Help users navigate and find content.
  • Making it easier to use inputs other than by keyboard.

Understandable: the guideline Relate To:

  • Make text readable and understandable.
  • Make content appear and operate in predictable ways.
  • Help users avoid and correct mistakes.

Robust: the guideline Relate To:

  • Maximising compatibility with current and future user tools.
  • For example, by using valid code.

For Each Principle

There are guidelines – these are the basic goals that authors should work toward in order to make content more accessible.

And For Each Guideline

Ther are ‘testable success criteria’.

  • Three levels of conformance are defined as: A (lowest), AA, and AAA (highest).
  • Techniques and examples are provided for meeting those criteria.

Mobile Platforms

  • All ‘success criteria’ apply to mobile platforms as well as desktop platforms.
  • However, the techniques sections does not yet fully cover mobile techniques.

Jim Byrne

Accessibility of audio and video content on the web

I have re-published this content from a report I wrote for The Spoken Word Project in March 2007 – because it occurred to me that this might be useful information for organisations thinking of adding video to their websites.

Time constraints mean that this document cannot be considered a definitive review of the subject of accessible audio and video content – however it should provide information that can act as a starting point for your own research into the area.

Delivering audio and video on the web

There is no perfect solution to delivering accessible multimedia content on the web. The huge range of user needs, computer and software platforms and audio and video format available – ensures that no one solution will cover all accessibility needs.

The choices for any publisher of video will include,

  1. Sticking to creating content for a single player such as Windows Media Player, Quicktime or Flash.
  2. Publishing each resource in multiple formats in an effort to ensure no one is left out.

With the first option some users will not be able to play the content, as they do not have a compatible computer or software. The second option may lead to cost and resource implications for the publisher that can’t be met – although if using tools that can export the resulting video in more than one format this is a route worth considering.

Some formats lend themselves to the creation of alternative content more than others. However, the most flexible or the most accessible format may not be the most widely used.

Youtube and the arrival of a new standard

The picture is complicated by the speed at which new ‘standards’ arrive on the web and changes in the functionality of existing formats, i.e., the extend to which a particular form is accessible changes as it is developed in line with new priorities. Flash is a case in point. Adobe reports the following statistics supporting its own case as the dominant player for web based video:

  • Flash Player is on 97.3%
  • Microsoft’s Windows Media Player is on 83%
  • QuickTime 66%, and
  • Real 56%.

It is in Adobe’s interest to report that their format is dominant, however this does appear to be the case in practice.

The rise of Flash for web delivery of video

There has been explosive growth in the availability and consumption of web video in the last couple of years – to the extent that a new dominant format has emerged. Flash has become the most popular way to deliver video on websites, certainly in relation to public consumption,

“in 2004 Flash Video was still a bit of a novelty. Two years later it is a standard. It is the video format of choice for two of the most popular sites on the web: YouTube and MySpace” Tom Green–the_rise_of_flash_video_part_1

According to Adobe-Macromedia, in less than one year Flash version 8 has been installed onto nearly 95% of the 765 million personal computers worldwide. The results is that “the Flash(R) 8 platform has grown faster than any other software in history.” (See–default.aspx)

Flash and accessibility

Flash has traditionally been seen as an accessibility problem rather than a solution – but this is no longer the case. Web accessibility experts – on the contrary – are now recommending Flash as the most accessible way to deliver web video. Flash was the only answer forthcoming from several members of the Guild of Accessible Web Designers, when I posed the question on the mailing list about the best way to deliver accessible video.

However the rising dominance of Flash means problems for producers who want to serve up flash. My limited research indicates that Flash server software is expensive and not yet user friendly enough for use in a production environment.

Andrew Kirkpatrick of Adobe had the following to say in reply to my questions about Flash Accessibility:

“For embedding video, you can make video with Flash more accessible than any other format.

You can provide captions for all media formats, but Flash provides access to the interface controls in a more robust way than other players (the typical advice for providing users withy access to the playback controls for other media players is to allow the media to load in the standalone player).

We have caption skins available for the Flash FLVPlayback component:–captionskins.html

These currently work with Captionate for captioning, but will someday soon also offer support for DFXP captions.

Today, NCAM (the WGBH National Center for Accessible Media) released MAGpie 2.02, which includes support for DFXP captions. DFXP, by the way, is the W3C’s new caption data format.

NCAM also released a new component for Flash that allows you to parse and display either DFXP or QT’s caption format, and includes an API for caption searching.–ccforflash.html

Granted he is speaking as a representative of Adobe, however, it is consistent with the views expressed by developers considering the most accessible format for delivering video on the Web.

Quicktime for video production

Quicktime continues to be the most appropriate solution for processing video prior to web consumption.

“The Flash video process starts with a source video–preferably a video in the QuickTime (.mov) format. There are two reasons behind this. The first involves the “GIGO Principle”: Garbage In, Garbage Out. We shouldn’t accept substandard artwork, audio, or other content, so it makes sense to apply those same quality standards to our video. The second reason is a matter of standards. The current industry standard is the QuickTime format, so it makes sense to request video in that format from your clients.”–the_rise_of_flash_video_part_2

Serve video as both mp4 and flash?

Quicktime videos can be exported to Flash for delivery on the web. This provides the option of serving videos in both mp4 and Flash.

Technology can change quickly on the web, however in the short to medium term Flash can’t be ignored as a potentially accessible vehicle for publishing video on the web.

My recommendation would be to consider either developing skills in-house in relation to Flash video development or to consider buying in a service that can provide assistance in developing resources in this area.

(See Niqui Merret Flash and Accessibility for further information, training and consultancy in relation to producing accessible Flash.

Audio formats

Audio in general is considered a highly accessible format, as it has benefits for print-impaired learners, such as people with dyslexia or blind or visual impaired users.

However, people who have a hearing impairment or who are deaf will have problems accessing audio. IMS Global Learning Consortium (see–sec5.html) outline the accessibility issues with audio as:

  • lack of captions and/or transcripts.
  • poor sound quality.
  • inability to control volume.

Streaming versus downloads

Streaming is generally preferred to downloading because users with lower bandwidth connection can get quicker access to the content. Streaming may also be the preferred option in the educational context as many University and college computer labs do not permit students to save downloads to local hard disks.

Combining audio and text for greater accessibility

Accessibility can be enhanced by providing captions and/or transcripts. Provide users with the ability to control volume and providing visual equivalents to sound alerts (i.e., a beep). Further accessibility enhancements could include transcripts or captions or sign language.

A format that makes this possible is DAISY/NISO (Digital Accessible Information Systemes/Nation Information Standards Organisation). .DAISY/NISO allows simultaneous presentation of text, graphics and audio format. However, players for this format are not yet widely available.

With the DAISY/NISO format, text is provided in a XML document and the audio is syncronized with the text using SMIL (Synchronized Multimedia Integration Language). Benefits of the DAISY/NISO format include:

  • Text and graphics can be provided along with the audio file.
  • Text and audio descriptions of graphics can be incorporated.
  • Navigation capabilities can be built in – allowing users to move around a document based on its structure.

The American Council of the Blind support the MAGPIE format,

“Individuals who read large print or have learning disabilities will also increasingly be able to benefit from reading files in this format. Currently, at least one reader allows people to control the font size or type, as well as change foreground and background colors to provide needed print contrast. People with learning disabilities are often able to track the text more easily when a player has an option to highlight words in the text while the user listens to the audio file.”–accessible-formats.html

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