Content Improvement Club is our regular meetup for web publishers. In January, we ran two sessions focused on writing alt text and making images accessible.

Last March, we ran a session outlining why alt text matters and key principles behind writing it well. This post builds on that session, so we recommend reading our previous blog first:

How to write good alt text (March 2025 Content Improvement Club session)

What we covered in our two January alt text sessions

This time, we wanted to explore more complex scenarios, share practical challenges and leave more time for discussion.

The level of interest in the topic led us to running two sessions. This allowed us to hear from a wider mix of colleagues across the University, which was really helpful. We got a clearer sense of the questions people have and the challenges they’re facing in practice. It was also great to see the appetite for the topic and that people are keen to get alt text right.

A recap of key alt text principles

We started by grounding ourselves in the basics. Even when we’re dealing with more complex examples, the fundamentals still apply.

A quick reminder of what to keep in mind when writing alt text:

• Communicate the key information conveyed by the image.

• Be concise (usually one to two sentences).

• Focus on what matters in the context of the page.

• Avoid unnecessary phrases like “image of”.

• Avoid using file names as descriptions.

Alt text is part of your content. It needs to be clear, purposeful and user-focused just like everything else on the page.

Ways of approaching alt text

We shared a couple of practical starting points for thinking about alt text.

One prompt we find useful: If you were describing this image to someone over the phone, what would you say so they understand what’s important?

We also repeated a simple but effective exercise from the March session where you turn off images in your browser and read the page without them. This is a quick way to test whether your alt text is doing its job.

We explored more complex alt text scenarios

Once we’d covered the basics, we moved into the trickier territory. Across both sessions, lots of the questions came down to judgement. Here are some of the themes we discussed.

Avoid using images of text

One of the key areas we’ve learnt more about since the last session is avoiding the use of images to present text wherever possible.

Text shown in images cannot be read properly by assistive technology, such as screen readers. It also cannot be resized or customised by users. Accessibility adjustments (such as colour contrast) cannot be changed within an image itself. Fonts used in images may also not be accessible or easy to read for all users. This makes it especially important that any essential information is available in an accessible text format.

If text appears in an image, that text must also be available as real text on the page. Do not rely on alt text alone to convey large amounts of written information.

The University of Limerick has helpful guidance on avoiding reliance on images of text, including examples of how to provide the same information in accessible text.

University of Limerick’s guidance on images of text 

Infographics

Infographics are a common challenge in a university context, where charts, diagrams and promotional graphics may be used regularly.

A useful question to ask is: What is this image adding to the page?

If you’re presenting information as an infographic, all featured text that conveys meaning to a user must also be included as alt text or presented as text on the same page.​

Alt text alone is rarely enough for complex infographics. In most cases, it works best as a summary of the overall purpose or key message, with the full detail provided clearly in the page content.

We’ve found it useful to refer to Harvard’s guidance on working with infographics. They include practical examples of different image types and how to approach writing alt text for them.

Harvard’s guidance on data visualisations, charts and graphs

Describe people in images respectfully

Several discussions focused on how to describe people in images.Colleagues raised questions about whether to reference gender, age or other characteristics, and how to avoid making assumptions based on appearance.

As a general rule:

• avoid assumptions about gender, ethnicity or background

• describe what is observable and relevant to the context

• don’t reduce people to stereotypes or visual tropes

For example, you can’t know someone’s gender just by looking at them, so in most cases it’s best not to state it.

Be mindful of inclusive language when writing alt text. The University’s Inclusive language guidance can help when you’re unsure.

University of Edinburgh’s Inclusive language guide​

Writing alt text for specialist, technical and creative content

Colleagues working with scientific, technical and creative content raised particularly nuanced challenges.

These included:

• how much detail to include for microscopy or laboratory images
• whether to use specialist terminology or plainer language
• how to approach images in academic papers
• writing alt text for artwork

In these cases, audience and context are key. On a specialist research page, technical terminology may be appropriate. On a public-facing page, clearer and more general language may be better.

For artwork, the approach depends on the context. If the materials or medium are important, include them. For example, it may be appropriate to begin with “A painting of…” or “An illustration of…”, rather than “This is an image of…”. Indicating the medium can help provide clarity.

If an image of artwork includes important contextual information (such as the artist’s name or title of the work), that may be better placed in a caption, rather than in the alt text itself.

As with other image types, be descriptive rather than interpretive. The focus remains the same: communicate the meaning and purpose of the image, rather than describing every visible detail.

AI-generated alt text needs human review

AI tools that generate alt text came up in discussion. They can be helpful as a starting point, but AI does not understand the context of your page in the way a human does.

Effective alt text depends on what the image is doing in that specific place. That nuance (what matters here, for this audience) still requires human judgement.

If you use AI-generated alt text, treat it as a draft. Make sure to review, edit, and check that it reflects the purpose of the image on your page.

As well as his excellent guide on writing good alt text, Craig Abbott has written about his experimentations with various AI tools and how they take on writing text descriptions. It’s an interesting read that shows how different large language models interpret images, but often miss the context needed to describe them well. Craig concludes similarly that anything taken from them requires human review.

Craig Abbott’s alt text guide

Can generative AI write contextual text descriptions? (Craig Abbott)

Managing alt text at scale

Time and scale were recurring themes.

Many colleagues are reviewing existing content where alt text is missing, inconsistent or outdated. That can feel overwhelming. There is no single right approach, but a few practical suggestions came out of the discussion:

• A place to start might be key or high-traffic pages.

• Build alt text into your workflow for any new content.

• Writing alt text takes practice – aim for improvements, rather than ‘perfection’.

The good news is that once you get into the habit of writing alt text, it becomes easier. Returning to older content to make improvements can feel less daunting once you’ve built confidence and consistency.

Find out more about accessible design

If you have questions about assistive technologies​ and accessible design,​ contact the University Disability Information Team​.

Disability Information Team

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Other training that we offer

More training is listed on the User Experience Service website:

Training | User Experience Service