What is alt text, and why is it so important for learning experiences?


lt text is a term you’re probably seeing more and more often around the web, particularly if you’re creating digital content. Have you noticed when you upload an image to your training course there's  a little box asking, “do you want to add alt text?”

But what is alt text? 

Alt text is incredibly important, so we’re going to break down what it is and why it’s so important without using any technical jargon.

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What is alt text?

‘Alt text’ is short for ‘alternative text’. Simply put, alt text is what appears when your chosen image does not appear. In other words, it is the text alternative to the image.

What does that mean? It means that if your image won’t load, the web browser or software that is hosting the image will display the attached alt text. Instead of an empty space, the user will be able to see a snippet of text explaining what the image would have been.

Therefore, alt text should always be used to describe the image as it is meant to appear.

However, the function of alt text doesn’t stop there. If it did, alt text wouldn’t be so important. After all, it’s rare to come across a malfunctioning image these days - technology and software have come a long way since images first started appearing on computer screens.

What is alt text? Why is alt text important?

Alt text is a critical accessibility tool

For users who are visually impaired, viewing images on digital devices can range from difficult to impossible. With today’s web and software design so richly visual, this can present a major barrier to participating in eLearning and the wider digital world. To overcome this barrier, many visually impaired users navigate with the assistance of screen readers.

What are screen readers? Screen readers are software programs that audibly relay the contents of a digital screen. In other words, they read aloud what is on the screen. They are able to read text, and interpret the coding of a program or web page to communicate if the text is in the form of a button, heading or other format.

Crucially, when screen readers reach an image, they will read the alt text aloud. Screen readers cannot “see” an image, so they rely on the description provided in the alt text.

Therefore, alt text is a critical accessibility tool, as it allows visually impaired users to engage with images and understand their meaning, which is often a critical component of navigating eLearning courses and other digital experiences.

Many organisations, companies and government branches mandate that all digital content including eLearning experiences produced by employees must be compatible with screen reading technology. Screen reader compatibility is also a fundamental requirement of the WCAG 2.1 standard of digital accessibility.

How to write great alt text

As mentioned, alt text is attached to an image and will display if the image does not appear, or if the user is navigating with the assistance of a screen reader. Because of this, it’s important to provide an effective description of the image. We’ve gathered our best tips for writing effective alt text.

Tips for writing effective alt text

  • Alt text should be succinct. Keep it to one sentence where possible, two at most. 
  • Alt text should always describe any aspects of an image that are relevant, meaningful or informative, and are not described elsewhere (such as in the caption or body text).
  • If the image contains important information such as a graph or diagram, this meaning or implication should be made clear in the alt text.
  • If the image contains any words, you MUST include these in the alt text. Screen readers are unable to read text that is embedded in images.
  • It is helpful to distinguish the style of the image, for example, whether it is a photo, illustration, cartoon or painting. 
How to write alt text and alt text mistakes to avoid.

Alt text mistakes to avoid

Once you have begun writing alt text for your images, it’s important to make sure that you don’t make the following mistakes:

  • Auto-fill  alt text. Many programs will take the file name of the image and use it to auto-fill the alt text description. This is unhelpful, as chances are, your file name is something that only makes sense to you, or is a jumble of words, numbers or other characters.
  • Repeating the same text as the caption. Screen readers are able to read captions as they are not embedded in the image. Use the alt text to provide additional details instead.
  • Including the words “image of” or “graphic of”. Screen readers already know to announce that the file is an image, so this becomes repetitive.
  • Labouring over alt text for purely decorative images. If an image doesn’t add any extra meaning, then keep the alt text description short and sharp, or even simply write “decorative photo” or “decorative illustration”.
  • Ignoring grammar, punctuation or spelling. These factors allow screen readers to sound natural, and are important for helping the listener to make sense of the description.
  • Using an image when you could have used text. If there’s too much information that you need to include the alt text, you may need to reconsider your use of an image in the first place. For example, if you have a table, try to display it as native text instead of embedded in an image. 

Alt text should be non-negotiable

Alt text is a simple and powerful tool for creating inclusive digital environments. Everyone has a right to participate equally in the digital world and alt text is a crucial enabler. So don’t skip or skimp on your alt text! It could make all the difference in someone’s experience of your eLearning courses.

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Jun 3, 2021

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