We believe online assessment should be available and accessible to all.

We strive to comply with the Web Content Accessibility Guidelines (WCAG) 2.1 on ("the website") at most of level AA requirements.

This statement covers the STACK website, and does not cover the STACK interface for teachers and students.

Steps taken

The main website,

  • functions at 200% zoom,
  • is responsive and usable on most common browsers and resolutions;
  • browsers tested on: Chrome, Firefox, Safari, Edge,
  • resolutions tested on: common resolutions for laptop, tablet and mobile,
  • ensures all non-text elements have alternative text,
  • never uses colour as the sole means of conveying information,

Known issues

  • The website is not compatible with Internet Explorer 11.
  • The website has not yet been tested with applications that increase/decrease text size only.
  • The website has not yet been tested with screen readers.
  • The navigation bar cannot be navigated with only keyboard beyond two levels.
  • The user map on /CaseStudies/Overview is not navigable by keyboard.
  • Some elements have a colour contrast ratio of less than 4:5:1, in particular the navigation bar.
  • The documentation website "" has not yet been tested for accessibility.

For comments or suggestions regarding to accessibility, please email Chris Sangwin at