Accessible PDFs Part 2: How to Write Alt Text

Here we cover alt text and provide guidance on how to get started. As a quick recap, alt text provides people using assistive technologies with an alternative way to access visual content. To make your documents accessible, alt text is required for all essential visual content. It is not required for non-essential visual content such as ornamental objects. In the first article, we introduced the changing laws around PDFs, how to prepare, and additional content you will need to produce when creating electronic documents, including alt text. If you are unfamiliar with this context, here is a link to the first article.

During the report design process, we move in three phases: content development, design and layout, then finalize and publish. Each stage needs to be substantively complete before we move on to the next. Alt text development happens during the design and layout phase. It is in the design phase that graphics are created or reformatted, and hotos are selected and placed. When we get to this point, we will produce a document that inventories each item that requires alt text so that it is easy for you to produce text for each item.

Write alt text in plain language

Alt text should be written in plain language. The International Plain Language Federation (IPLF) defines plain language as follows: “A communication is in plain language if its wording, structure, and design are so clear that the intended readers can easily find what they need, understand what they find, and use that information.” 

A few plain language writing tips to consider when developing alt text:

• Know your audience: Plain language does not mean watering down your content; it means making it simple to understand for your target audience(s). That starts with asking, “Who is this product for and what are they trying to do with it?”
• Write in the active voice. Writing in the active voice makes your content more direct and succinct, and it often sounds more natural. 
• Write in the positive, not the negative. Negative framing requires your reader to hold two ideas at the same time — what you want, in contrast to what you don’t want. For example, “Don’t go outside during a hurricane,” becomes “Stay indoors during a hurricane.”
• Write in short sentences and paragraphs. Shorter sentences and paragraphs are more inviting, easier to understand, and easier to skim.

Alt text for photographs

Consider using some creative license when writing alt text for photographs. Try writing in narrative form. Instead of saying, “A woman sitting on a bench in a park,” try something like, “A young woman sits peacefully on a bench, sipping a cup of tea, as children play in a nearby park.” One description paints a picture while the other does not. 

A narrative approach may be especially valuable if the photo was chosen to evoke a specific experience. Imagine a report written about race cars and a featured image of a red race car blurring as it roars down the track. Alt text that reads, “Red race car on track” would be an injustice to the reader.

Alt text for charts, graphs, and figures

Here is a simple formula to use when writing alt text for figures:  [Chart Type] of [Variables/Axis], showing [Key Trend or Takeaway]. For figures with dense, multi-series charts, alt text is not meant to replace the underlying data. For anything too complex to summarize in a few sentences, the image may need a linked data table or longer description elsewhere.

Check out this article on the official Section 508 website for more guidance on writing alt text for figures and a deeper dive on alt text in general.

There’s no need to write “Image of…” or “Picture of…”

The image will be tagged, and assistive technology will tell the reader that this is an image. Your alt text can simply read, “A young woman sits…” not “Image of a young woman sitting…”

Keep it short and sweet

One or two sentences is sufficient for most images. If your image is dense or has a lot of data, provide the necessary content so that your reader understands the full meaning behind the image. But keep in mind that while there is no standard rule, most guidance suggests keeping alt text focused.

Don’t trust AI-generated alt text

On the Adobe InDesign Community forum, users report extremely offensive content produced by the AI-powered alt text generator that was released in early 2026. While this feature is enabled by default, it can (and should) be disabled. This is a good lesson for us all to lean on the AI tenet of “human in the loop” which reminds us that a human should always review content produced by AI.

For more information about Adobe InDesign’s AI-powered alt text, check out the article produced by Creative Pro.

The Bridge Studio is here to help

If you are preparing for your next report design project, we’d love to connect. Contact us to schedule a free consultation.