Principles for web content accessibility

The industry standard guidelines for web content accessibility are organised around four principles: Perceivable, Operable, Understandable, and Robust (POUR).

Perceivable

Users must be able to process information. Information that is not presented in a processable format is not accessible. This means providing text for those who cannot hear, and audio for those who cannot see. Content must work with screen readers and other assistive technologies. Is there anything on your web content that a blind, deaf, low vision or colourblind user would not be able to perceive?

• Ensure the standard font colour and background colour have a good contrast ratio e.g. dark text on a light background
• Ensure that a sans serif font is used which is large enough.
• Provide transcripts for audio clips and subtitles for videos. See our video guidance for using automatic captioning in Panopto (opens in a new window).
• Provide alternative text for all images, charts and graphs (make sure all images have a meaningful written description).
• Enable tooltips by default, so that a written description of any image automatically appears when you hover your mouse over it.
• Make it easy for people to change font size, colour and contrast.

Operable

People with disabilities need to be able to operate websites with a variety of tools. Many users with disabilities cannot operate a mouse. Alternatives such as keyboard-based operation should be available.

• Ensure pages and site can be navigated using the keyboard rather than only by mouse.
• Ensure that no information is conveyed only by sound or colour.
• Avoid any scrolling or flashing text.
• Ensure that users have as long to look at a page as they wish (i.e. no time-limited content)
• Alert users when content opens in a a new window.

Understandable

Understandable websites use clear, concise language and offer functionality that is simple to comprehend. Navigation should be used consistently across a site. Forms should follow a logical flow and provide clear labels.  Is all of your text clearly written? Are all of the interactions easy to understand?

• Ensure that your content and structure is consistent and readable
• Ensure pages are clearly structured using style sheets, text is broken up by sub-headings
• Ensure that language is simple and appropriate.

Robust

All websites should work well enough across platforms, browsers, and devices to account for the needs and personal choices of your users. .

• The website should be compatible with assistive technology such as screen readers. Plain HTML is easy for such technologies to convert.
• Include a link to the university's accessibility statement (this appears as standard at the bottom of university website pages).