What makes a good alt text description?

Note: “alternative text”, or “alt text”, is a short description you add to pictures on the internet. You cannot see the text on the screen but screen readers like Microsoft Narrator and JAWS will read the text aloud.

Keep it simple

Describe the image to someone who is blind or has low vision. Do not use complicated words or jargon that a person might not understand. The alt text should not be longer than a sentence or two.

Block capitals

Please do not write in block capitals. They create barriers to accessibility for many individuals, including those with disabilities or learning difficulties. Using mixed cases can help ensure that information is accessible to everyone.

Website links

Please do not add website urls to the alt text field. Users will not be able to click any link.

Location

Please do not add an address to the alt text field. You can add this in Step 3 of this form.

Prioritise key details

Stick to the most relevant details to keep the alt text concise.
You do not need to describe everything, just what matters most.
For example, mention the people in the photo, the event, or
anything prominent.

Test for clarity

Ask someone else to read your alt text and see if they understand what is happening in the image. If they do, you are on the right track.

Do not add “Photo of”

It is not necessary to include phrases like "Photo of" or "Image of" in the alt text. People will understand that they are viewing images.

Leaflets

If adding a leaflet as an image, the information on the leaflet must be added to the alt text field. This way, the information is accessible to everyone. When text is embedded within an image, it cannot be read by screen readers.

Example of an alt text description:

Two hands, typing on a laptop keyboard. The screen displays the word ALISS.

The alt text is simple and provides a basic idea of what the
image is about.

Why is it important to have good alt text on an image?

Inclusion for everyone

The alt text ensures that people who use a screen reader can
understand who or what is in the image.

Helps search engines

Alt text provides information to search engines. Search engines
like Google use alt text to understand what the picture is about.
This helps them show the right pictures when people search for
things.

Internet problems

If pictures do not show up due to problems with the Internet, the
alt text appears instead. This way people know what the picture
was supposed to show.