Tech, Explained · Website basics
Alt Text vs. Caption: Does the Text Below an Image Do the Same Job?
You can see the description underneath a photograph. So why does someone keep asking for alt text as well? Because those two pieces of writing help people in different situations.
The short answer
Alt text is a text alternative associated with an image. It communicates the image's meaning or function when someone cannot see it, including when using a screen reader. A caption is visible text displayed with the image. It might identify a person, explain a location or add context. A caption does not automatically become the image's alt text, and the best alt text is not always the caption copied into another box.
What this means in everyday life
Picture a service page showing a technician inspecting equipment. A caption could explain what the inspection includes. The alt text should convey whatever the image contributes to that particular page. If the photo is merely decorative and the surrounding text already conveys everything useful, empty alt text can be appropriate. If the image is a button, its alternative should communicate the action or destination, not simply describe its colors.
Where the misunderstanding causes trouble
This is not a place to hide a list of search phrases. Repeating your city and service name in every image description creates a poor listening experience. Nor should every image begin with 'image of': the screen reader often already identifies the element as an image. Complex charts may need a nearby explanation or data alternative rather than a very long alt attribute.
A practical business example
Here is a hypothetical example. A remodeling company publishes a before-and-after kitchen comparison. Both pictures originally have 'best remodeling contractor' as their alt text. That tells a screen-reader user almost nothing about the transformation. The revised page describes the relevant change, such as replacing a narrow doorway with a wider opening, and explains the project in visible copy. The photos now support the story instead of functioning as keyword containers.
What to ask before deciding
When you commission website content, ask for image alternatives as part of the deliverable. They should be reviewed alongside headings, links and forms, not treated as an optional SEO extra. For genuine project photos, the description must match the actual image. For illustrative images, do not imply that a pictured person is a real customer or that the scene documents a completed project.
One useful next step
Review a few important images in their actual page context. Ask what a visitor would miss if the image disappeared. Then supply that meaning in the most useful place: concise alt text, a visible caption, surrounding copy, or a fuller text alternative. Check the finished page rather than assuming your CMS field has rendered correctly.
The takeaway
Alt text and captions are teammates, not interchangeable boxes. Start with what the image helps someone understand or do, then write the alternative and visible explanation around that purpose.
Accessibility includes more than image descriptions, and your content management system needs to preserve the alternatives you write when it publishes each page.
Questions you might still have
Should a company logo have alt text?
Usually it needs an alternative identifying the company, but context matters. If it is a link to the homepage, the accessible name should also make its purpose clear. Avoid repeating information already supplied by an equivalent adjacent link or accessible label.
Does every decorative image need a description?
No. A genuinely decorative image can use empty alt text so assistive technology can skip it. Make that decision from the page context, not the file type.
Can alt text help search engines?
It helps explain image content, but its first job is a useful text alternative. Keyword stuffing does not make an inaccessible or misleading description better.
Source: Source explanation from w3.org.
Put the explanation to work
If this raises a question about your own website or marketing, explore Guardian Solutions’ website design and usability services or tell us what you want to improve.