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Our website's accessibility principles

We really want to make sure this website is accessible to as many people as possible. Here's a breakdown of what we have done so far. If you have suggestions for how we could improve this, or find any problems with what we have done, please get in touch.


  • The smallest font size on this website is 14 pixels in height, for image captions.
  • All heading text is legible against the page background, with a contrast ratio of at least 3:1.
  • All body text is legible against the page background, with a contrast ratio of at least 4.5:1.
  • Text is structured with nested headings, presented in a meaningful order, which describe the topic or purpose of the content.
  • Text can be resized without loss of content or functionality.
  • Text in images is purely for decoration, or where crucial it is also available in normal text.
  • Any unusual or industry-specific words and phrases are explained in simple English.
  • The full form is included wherever shortened forms like abbreviations, initialisms or acronyms are used, for example: Software as a Service (SaaS). 


  • The text of all links is descriptive (or if this isn't practical we provide alternative text) to make its purpose clear.
  • The first link on every page bypasses the navigation to move straight to the content. This is hidden by default in a standard browser but is accessible in appropriate scenarios.
  • Page addresses (URLs) are readable by humans and are permanent wherever possible.
  • All links and buttons have a keyboard focus indicator which makes them clearly visible.


  • Unless they are just for decoration, all images have alternative text (an “alt” attribute) which is shown where images are disabled, or where they are not supported.
  • Content is accessible and understandable with images disabled, or where they are not supported.



  • All form controls and fields are properly and clearly labelled.
  • All crucial form fields are checked for errors when the form is submitted.
  • Any error found is described to the user in text, along with suggestions for how to correct the error.
  • All forms have a correct focus order so they can be navigated using the Tab key on your keyboard.
  • All forms can be submitted using the Return ↵ or Enter key.


  • We use unobtrusive client-side (on your computer rather than on our server) scripts.
  • This website is fully accessible with Javascript disabled, or where it is not supported.

Visual design

  • This website uses cascading style sheets (CSS) for visual design and layout. 


  • This website is accessible from smartphones and tablets.
  • Page layout and content respond to the size of the browser window to make best use of the space available.
  • Buttons and navigation have a minimum height of 36 pixels for ease of use on touch interfaces.
  • The menu (navigation) collapses on smaller devices to save screen space. It can be reopened with the "more" button in the top right corner of the site.


Our efforts to make this website accessible were guided by the following resources: