We all know that digital accessibility is really important and needs to be prioritised whenever content is created. But sometimes, knowing where to start can be tough. This blog covers the basics of the alt text, why it’s important and what good looks like.
What is alt text?
Alt text (alternative text) is the text explanation you provide alongside images in digital content. This means that anyone who can’t see them, for reasons of disability or pages being slow to load, understand what the picture is of. You would include alt text alongside any of the pictures you have within content. Without this, any users using screenreading technology will either skip the image altogether or offer a notice to the user saying that no description is offered. This excludes people from your content and provides a poor user experience which isn’t fair or legal. After all, all public sector websites and mobile apps should be accessible, meeting the Public Sector Bodies (Websites and Mobile Applications) (No. 2) Accessibility Regulations 2018.
How to write good alt text
Your alt text should be around 125 characters long max and shouldn’t start with “a picture of” or “image of”. With limited characters you need to be concise.
If you’ve got captions, don’t duplicate them in the alt text. Captions don’t need to explain what it is in the picture. For this picture, the caption could be “Dogs need regular veterinary treatment to ensure they’re kept in the best condition”. But the alt text would describe the image, such as “a golden retriever sat on a veterinary table with a vet wearing a white coat holding its paw, looking at it and smiling”.
Don’t assume things in the picture. Things can get subjective and inaccurate quickly if you’re trying to describe a person’s gender, ethnicity, race, clothing, hair, accessories, etc.
Don’t use a file name, duplicate text, or URLs as alt text.
If the image is a graph, the alt text needs to explain what type of graph it is and what it is showing. An example would be “Line chart showing that the amount of helpline calls is rising over the course of 2019 to a peak of 72% in November 2021”.
If you can be specific about what the image is showing, then do – if the picture shows Plas Newydd gardens in Anglesey, then put that into the alt text.
Explain the context: Are people smiling? Is someone sitting in a darkened room? If it adds to the user’s understanding, include it.
Always ensure that if you have a bilingual site, the alt text is translated correctly so you’re not limiting users who consume their content in that language.
Alt text for accessibility is one of the main areas that people forget to consider when creating and publishing accessible content. Keeping these alternative text considerations in mind when you next create content will help to ensure that everyone is able to comprehend the imagery that you’ve chosen.
Interested in learning more about accessibility? We’ve got three blogs about Making Things Accessibility, What Do Accessibility Regulations Cover? and Accessibility for Different Content Types that you can read.
If you have any questions, you can comment below, or email us at firstname.lastname@example.org