This is a sponsored post paid for by Just Content.
Writing and editing alt text is a mainstream service at Just Content, and we are pleased to say that Alt Text Services are standard for the majority of digital projects that we work on.
Why are we pleased? Because without effective alt text, visually impaired users are unable to use screen readers to describe illustrations (artworks and photos) to them.
For editors who are new to writing and editing alt text, you might be wondering where to start. Well, you’re in luck. We’re sharing our answers to some frequently asked questions to help you to ensure that your content is as accessible as it can be for as many people as possible.
What are screen readers?
Screen readers are software applications that read out the text of the content on a digital device to visually impaired users. Some examples:
- JAWS (‘Job Access With Speech’), Windows
- NVDA (Nonvisual desktop access), Windows
- Narrator for Windows, included in Win 10/11
- Voiceover, Apple devices, installed by default
What is alt text and how does it help visually impaired users?
Illustrations do not usually contain readable text, so alt text provides a description of an illustration that a screen reader can read out. Alt texts can vary in complexity, depending on what is being described. For example
Simple Alt Text (for a KS1/equivalent Reader):
There is a photo of a cat wearing sunglasses.
Where is Alt Text stored?
Alt text is stored as metadata – attached to the artwork. Here is an example from MS Word:
A screenshot of the ‘Format Picture’ dialogue box opened in Microsoft Word. It shows the alt text fields ‘Title’, which is blank, and ‘Description’ which is populated with the following text: ‘Diagram to show a sodium atom and a chlorine atom. The sodium atom has circles with 2, 8 or 1 red dots on them. The chlorine atom has circles wit 2, 8 or 7 blue dots on them. An arrow points from the outermost red dot of sodium to a gap in the outer circle of chlorine.’
What are the most important things to consider when writing alt text?
A good place to start is the purpose of the illustration. Is it included to break up the text (non-functional alt text) or is it conveying essential/instructional information to the reader (functional alt text)? This will help to inform the level of detail you will need to provide in your alt text.
Think about what information the reader needs from the description. Use this to decide what is necessary and what can be left out.
Finally, when the illustration is part of a question (for example within educational content such as textbooks or exam papers), consider how you can write the alt-text without giving the answer away.
What writing style should alt text take?
- Remember that alt-text is a script, not prose and should not be any longer than is necessary.
- Write your alt text as if you were talking to a reader sitting beside you who is unable see the artwork you are looking at.
- Be careful not to leave room for ambiguity – spell things out in full but as clearly and concisely as possible.
What about numbers, units etc?
- Always write ‘0’ as ‘zero’.
- Always write ‘point’ for decimal points.
- Write abbreviations in full for units.
- Write mathematical operators in words, not symbols – e.g. add, subtract, times, multiply, divide etc.
- Add a space in between each character, e.g. angle A B C, line D E. If you don’t do this, some screen readers will try to read it as a single word. For example, for an extract from a bus timetable:
|High street, outside PO
Write time with an entry for the hour and an entry for the minutes, separated by a space, e.g. 13 40.
- For hours on their own, e.g. write 13:00, as ‘13 hundred hours’
- Where there are initial zeros, e.g. write ‘13:05’ as ’13 oh 5’
Make sure you know how tables are being treated in the output files: as artwork or text? Alt text is only needed for artworks. As a general rule, for a table with 5 rows and 2 columns or less, alt text is not needed.
If your table is any longer than this, then a long description will be needed.
What is a long description?
For very complex illustrations, or data-heavy artworks (for example, a graph with more than 5 data points), both a short and long description can be provided.
Here is an example of short description alt text (for a GCSE/equivalent exam paper):
There is a graph showing the results of an investigation into how the flow of air affected the rate of transpiration in a plant. See long description.
Here is an example of a long description:
The long description text is black text formatted in basic HTML. It appears in five columns. It includes the main alt text as well as the HTML code needed to form the long description.
Long descriptions are created differently to short description alt text. They:
- Are presented as a table in basic HTML.
- Do not have a style sheet (CSS).
- Will also include the main alt text provided.
- Usually go into a separate field (but not in MS Word!).
To generate your long descriptions, you can use the Tables Generator website to generate the HTML code (https://www.tablesgenerator.com/html_tables).
A screenshot of Tables Generator, showcasing how to set the size of your table using the Set Size function and selecting the number of row and columns the table will have.
A screenshot of Tables Generator, showcasing the table, above, and the long description text generated from the table, below.
Whenever you are working on projects where you are writing and editing alt text for complex artworks, the briefs you are provided with should always include guidance on long and short descriptions. If in doubt, our advice would be to ask the client for the details you need.
How do I provide alt text?
The process for adding alt text will vary depending on the project and the software or programme you are working on. We often input alt text via metadata tables (in MS Excel/equivalent) or we might be working directly within authoring platforms or content management systems.
How do I know I am doing it right?
As with any new task, we would always recommend sending a sample of early work for feedback, on the efficacy of the alt text itself and its suitability as metadata for the files your content will be stored in. It’s an important thing to get right and whoever has briefed you to do the work will want to support you to ensure that the content you are working on is as accessible as it can be.
With thanks to Jim Newall, Freelance Editor and Alt Text Expert, on behalf of Just Content.