Content Improvement Club: what we covered in our March session
Content Improvement Club is our regular meetup for web publishers. This month, we looked at writing and improving alt text to make images accessible to all users.
Our revamped content improvement meetups
We recently launched Content Improvement Club, a series of meetups aimed at staff who work with web publishing at the University. The meetup builds on similar sessions that we ran in 2024, and is based on two ideas:
- Learning more about creating effective content
- Working on your existing content with other publishers
This post covers some of what we discussed in this month’s session.
Use alt text to describe what people are seeing in the image
This month’s focus was on how to write good alt text and why it’s important.
Alt text (short for alternative text) provides a written description of images, conveying their meaning for users who can’t see them. Here’s an example of alt text on the University website and its corresponding image.
The card displayed with alt text instead of the image.
The card displayed with the image.
Understanding assistive technologies and alt text
Assistive technologies such as screen readers rely on alt text to convert content (such as text, buttons, images and other screen elements) into speech or braille. This allows a blind or partially sighted users to access the same information as sighted users.
In our session, we watched a short video demonstrating how a screen reader reads alt text aloud.
Screen Reader Demo video (YouTube)
Why alt text matters
When adding an image into your content, including alt text ensures that all users can access the information it provides. As online content grows, accessibility becomes increasingly important.
Images add meaning
Images contribute to a page’s overall meaning. Alt text allows for this meaning to be available to all users. According to the RNIB, around two million people in the UK live with significant sight loss. As they explain:
Alt text is important because it gives blind and partially sighted people access to the same images sighted people enjoy, but through descriptive text.
Find out why alt text is important | RNIB
Alt text improves user experience
Missing or improper alt text is a major barrier for screen reader users. WebAIM’s research ranks it as the sixth most common accessibility issue, a problem consistently highlighted in their surveys over the past 14 years. Since alt text is something we can control, it’s essential to make it meaningful and include it wherever possible.
WebAIM’s screen reader survey results
Alt text also benefits users with slow internet connections, where images may fail to load. Well-written alt text ensures content remains accessible in different circumstances.
Alt text is an essential part of web accessibility
Including alt text isn’t just good practice, it’s a legal requirement. The Web Content Accessibility Guidelines (WCAG) state:
All non-text content that is presented to the user has a text alternative that serves the equivalent purpose.
Writing good alt text takes practice
Images help make content more engaging, but their purpose varies. When writing alt text, ask yourself: What does this image add to this page?
Good alt text should:
- communicate the key information conveyed by the image
- explain both the content and purpose of the image
- be clear, relevant, and to the point
Key principles for writing alt text
Alt text should be treated like any other digital content. Keep it as concise, clear and jargon-free as you can make it. Keep these three principles in mind:
First, keep your alt text short. One to two sentences is usually enough. Avoid unnecessary details that don’t add value.
Secondly, describe the key details. Focus on what is most important about the image in the context of the page. The right level of detail depends on the purpose of the image. Craig Abbott’s guide offers a useful breakdown on striking the balance between alt text that is too vague and too detailed.
Finally, consider the context. The same image might require different alt text depending on where it appears and how it is used.
For example, an image of McEwan hall might appear on a webpage about graduation ceremonies, where the alt text could be: “McEwan Hall, the ceremonial venue for University of Edinburgh graduations.” The same image of McEwan Hall may be used on an events page, where the alt text might be: “Exterior of McEwan Hall, where the upcoming lecture will take place.”
By adapting the alt text to fit the context, you ensure it provides the most relevant and useful information.
Alt text is often subjective, and what works in one situation may not work in another. Writing effective descriptions requires practice and good judgement.
Things to avoid when writing alt text
Avoid unnecessary words. There’s no need to start with “image of” or “picture of”, as screen readers will add that information in by default.
Don’t use file names as your alt text. These usually have little relevance to the image and won’t be useful in describing the image. Remember, alt text should be meaningful and descriptive.
Sometimes writing alt text can be more challenging
As a group, we discussed some of the challenges that arise in a university setting:
- Infographics and images containing text are becoming increasingly popular. All text in the infographic must also be presented as text on the same page.
- Graphs and diagrams require specific approaches. Harvard University’s guidance provides useful strategies
- Being mindful of inclusive language is important. Avoid making assumptions based on appearance. For example, in general, don’t state gender of a person in the image, on the basis that you can not say what gender someone is by looking at them. The University’s inclusive language guide is a useful reference when it comes to considering what words to use.
Harvard’s guidance on data visualisations, charts and graphs
Checking the effectiveness of your alt text
One way to test your alt text is by turning off images in your browser. Most browsers allow this – check their guidance pages for instructions. This lets you experience your content as a screen reader user might, helping you assess whether your alt text conveys the right information. It’s also a useful way to see how alt text is used on other websites.
Another approach is to use a screen reader. Hearing how a page is read aloud can help you evaluate whether your alt text is clear and useful. NVDA is a free screen reader that you can download to test your content.
For more insights, Axess Lab has gathered helpful videos demonstrating screen readers in action.
Axess Lab – What is a screenreader?
Session activities
After our discussion, attendees worked in pairs to assess and improve the alt text on their own websites. They explored their pages with images turned off, selected an image to assess, and suggested improvements to the existing alt text.
At the end of the session, we shared observations and takeaways. Attendees left with practical ideas for making their content more accessible.
Find out more about accessible design
If you have questions about assistive technologies and accessible design contact the University Disability Information Team
How to hear about our next session
We’ll promote our next session via our mailing list. If you’re interested, please sign up:
Join the UX and Content Design mailing list (University login required)
Other training that we offer
More training is listed on the User Experience Service website:
