Accessibility tools and resources - Content

Useful articles on accessibility.

Write content that's easy to understand

Clear content helps everyone and it's the most important thing you can do to make things accessible. It will help more people than any other accessibility requirement.

HS2 services should follow the content guidelines.

Set page titles

A good page title helps users find what they want and recognise they're in the right place. It's the link that shows in search results and the first thing a screenreader will read out when the user lands on a page.

Each page title must be unique and descriptive. Keep it concise and consider putting important keywords near the beginning.

Best practice for page titles

Best practice is generally: Page name – Site name

For example: About HS2 – HS2

The first element (here "About HS2") is the main heading of the page.

If you can, use templates to keep things consistent and use your content management system to generate what comes after dash.

Use headings correctly

Everyone relies on meaningful headings to navigate the page but they are especially important for some people with access needs. Make sure your headings reflect the page structure.

Structure headings for accessibility

The H1 is the same as the page title. You should have only 1 H1 on a page.

Each main section of your page should start with an H2 and each sub-section of an H2 with an H3. It is possible to have sub-sub-sections which start with an H4.

With each heading, ask yourself if it's a sub-section of the previous heading. If not, it should be at the same level as (or higher than) the previous section.

Make sure that headings follow the correct "nesting" order and don't skip levels. The structure of the page is the key thing, not the size and style of the text.

You can use a web developer toolbar (Chrome or Firefox) to see the overall heading structure of the page.

Read more about styling headings in the typography section of the service manual.

Links or buttons need to make sense out of context as some people experience them that way. Each link should clearly describe where it will take you. For example: "Find out where your nearest HS2 station is".

How to write good link and form control names
  • Ideally link text should match the heading of the target page. If the target page has the heading "HS2 stations", that's good link text.
  • If the target page heading is too long, shorten it but use words from it so that users can predict where the link will take them.
  • Avoid ambiguous phrases such as "click here", "read more" and "find out more". It's OK to say: "Read more about our line of route."
  • Avoid having links or buttons open new windows or tabs. If you need to open a link in a new window, say this in the link phrase. For example, "Link name (opens in new window)".
  • If the link goes to a document, include the file type and size in the link phrase. For example: "Link name (PDF, 200KB)".
Using the same link text for multiple links

You can use the same text for multiple links when they're in a good structure. The table row headings together with the link text must make the meaning clear.

There's an example in the summary list component in the GDS design system. At the end of each row is a link that says: "Change". The context makes it clear what "Change" refers to.

Label form fields clearly

Make sure that every form field has a label that tells users what information they need to enter.

More about labels

Put the label next to the form field so that the user is clear which field it relates to.

Generally the label should be visible. (There are exceptions. For example, there's a hidden label "Search the HS2 website" on the search box in the HS2.UK header. It doesn't need a visible label because people can see the search icon and the word "Search" in the box.)

Give grouped items a "legend". You can see examples in the checkboxes and radios components in the service manual.

To test the code is correct, you can usually click on the label and the field should be focused by the browser. Otherwise, check there is a "for" attribute on the label and that it matches the "id" attribute of the field.

Highlight errors in forms

Make sure that error messages clearly describe what went wrong and how to fix the problem.

Include an error message wherever there's a problem with the input and check that it's visibly obvious that the message is connected to that input.

If you have an error summary at the top of a form, check that each error in the list has a link that moves the focus to the relevant form field. This helps users who rely on keyboard navigation.

Use the error message and error summary components in the service manual. They've been tested for accessibility and contain links to useful GOV.UK guidance on writing good error messages.

Use alternative text for images in content

People who cannot see a meaningful image need an alternative to understand the content. You need to add "alt-text" to explain what's in the image. Alt-text is not usually visible but is read out by screen readers or displayed if an image does not load or if images have been switched off.

You can see what alt-text an image has by viewing it with Chrome's Web Developer toolbar.

Informative images

The content of the alt-text depends on the image and its context. If the image is part of the main content of the page (not a functional image - one that triggers an action), use the alt-text to describe the image in a way that makes sense in the context.

You don't need to explain that it's an image because screen readers usually announce that.

Keep alt-text to a sentence or 2 and ideally under 125 characters including spaces. If there's important information that you cannot fit in 125 characters (for example, you're describing a complex chart), include this information in the alt-text or consider linking to more information for screen reader users. (For example, the HS2 website team is testing long descriptions to describe images of conditions appearing on a range of skin tones.)

Imagine you were reading the page out to a friend. How would you describe the image?

This is an image from the 'Building HS2' page on the HS2 website. It's displayed above a heading "Stations". The alt-text is: "Artist's impression of Birmingham Curzon Street Station." It explains what users can see in the picture.

Artist's impression of Birmingham Curzon Street Station.
An artist's impression of the new HS2 station at Birmingham Curzon Street.

This example has a caption underneath the image as well as alt-text. Read about captions and how they work with alt-text in the images component.

If you have a complex image that you cannot describe in short alt-text (such as an infographic), include a longer description in some other way on the page.

If your image has text which conveys its meaning, follow the guidance on functional images. An example would be a link to a health app which includes a brand image and the name of the app. The app name says the same as the brand image, so the image doesn't need explaining.

Decorative images

Decorative images are there to attract users' attention or motivate them, but they don't help users understand the topic. An example might be an image of a hard hat on a construction page.

If your image is decorative, give it a null text alternative like this: (alt="").

Use tables to show relationships between data

Tables make it easier for users to understand logical relationships between bits of data or information.

Only use tables when there is a relationship between the "header" cells and the "data" cells in the grid. Assistive technologies announce the header with the data it refers to.

Example of good table layout

Here is an example from the tables component in the service manual.

Forthcoming events
Event Location
Community engagement Birmingham
Community engagement Manchester
Community engagement London

Screen readers would read out the last row as: "Forthcmoming events: Community engagement. Location: London".

Make video and other multimedia content accessible

Consider using video as well as text. Some people find it easier to understand.

With all video and animation, make sure that:

  • the interface is accessible for keyboard and screen reader users (including play/pause buttons and the location slider)
  • if the user cannot see or hear it, they can still understand it

To meet the accessibility regulations for public sector organisations, most new videos you've published or updated after 23 September 2020 must have these 3 kinds of alternative content.

Audio description

Audio description provides content for people who are blind or cannot see the video well. It is additional commentary that describes what's happening on screen in between narration, including any text, graphics or scene changes in the video.

You must include an audio description for any key information that's visible on the screen but not part of the soundtrack, for example diagrams without a verbal description. If all the visual information in the video is included in the regular soundtrack, you do not need an audio description.

If the video says the same thing as the page content, you do not need an audio description but you must make it clear that the video is an alternative to the text content. Our experience tells us, however, that even in these cases audio description can be valuable to blind people, some of whom do not read the page content.

For audio description, you can do 1 of the following:

  • publish an alternative version of the video with audio description added in relevant places
  • add a separate audio description track (if the media player supports this)

If you have a separate audio description track, make sure it includes the audio description voice-over and the original video audio (mixed and synced together). The audio description track must be the same length in seconds as the main video’s audio.

Closed captions (sometimes called subtitles)

People who are Deaf or have hearing loss may find captions helpful. Closed captions are a text alternative to audio information in video and animations that you can turn on or off.

Use closed captions rather than subtitles. They look similar but subtitles are only a text alternative for dialogue, while closed captions are a text alternative for all the audio, including important background noises.

Closed captions must include:

  • the words people say
  • who is speaking, if it's not obvious, or where they are (for example, off-screen)
  • important sounds like music, laughter or a door slamming

Check that any auto-generated captions are accurate and synchronise them with the visual content.

Use a contrast ratio of 4.5:1 for the text. If possible, use a fully opaque (no transparency) coloured box behind the text. We recommend a black background with white text. Find out more about using colour and accessibility, including colour contrast.

For caption fonts, follow the typography guidance in the design system.

Transcript

Transcripts provide audio and video content for people who:

  • are both Deaf and blind
  • people who process text information better than audio and visual information

It's best practice to provide a transcript for a video but it is not required to pass WCAG2.1 AA. You must, however, provide a transcript for any audio-only content, such as a podcast.

A transcript should include all the dialogue, relevant sound effects, and audio description content.

There are rare exceptions, and you do not have to meet these requirements with videos published before 23 September 2020.

Do not rely on colour or position alone

Do not rely on colour to convey meaning, for example, an instruction. To communicate with people who cannot see well or distinguish colours, you may need to:

  • word things differently
  • use more than one visual cue, for example, text and an icon as well as colour

Do not rely on people understanding instructions that refer to the position of page elements.

Why you should not say "Press the red button on the right"

If someone is:

  • "colour blind", they may not be able to tell the difference between red and green
  • zoomed in, the button may not be on the right
  • using a screenreader, they may not see the colour - and position, for them, is simply up or down

Use HTML rather than PDFs

Avoid using PDFs as they are not accessible. If you must use a PDF, make sure the content is also available in HTML form.

Read more about PDFs and other non-HTML documents in the content guidelines.