By User Media on
Image alt text: when a photo only decorates, the field stays empty
A product photo names the feature that drives the purchase; a promotion, its offer and condition; an image that only decorates gets an empty field.
Image alt text is the phrase a screen reader reads in place of the photo, and the one that appears when it fails to load. In HTML it goes in the alt attribute of the img tag, and Google uses it along with computer vision and the page’s content to understand what each image is about. That is why describing what the image contributes works better than repeating keywords.
What is alt text, and what should it say about an image?
Alt text replaces visual information with words that serve the same purpose. WCAG 2.2 criterion 1.1.1 requires a text alternative for non-text content when it provides information or a function. The wording should let someone understand what changes for them even when the image does not load or cannot be seen.
The description changes with the image’s role on that particular page. A product photo can name the model, color, and deciding feature; an atmospheric photo beside a heading that already says the same thing may not need a description.
How do you write useful alt text for a product photo or website hero?
A strong commercial description names what helps someone decide to buy. On a product page, “Black waterproof backpack with a padded laptop compartment” conveys model, color, and use; it fits the online stores we design, where photo, name, and price need to work together.
A hero image needs to describe its specific contribution, not a generic scene. If a meeting supports a service, the alt text can say who is participating and what they are doing; if the heading already conveys that idea and the photo only sets a mood, it is decorative.
A file name never explains what a person needs to understand. “IMG_4832.jpg” and “photo of an image” do not replace a description. The title attribute does not replace alt text either: a visible caption has a different job and should remain separate.
When should I leave the alt text field empty?
A decorative image should stay out of the assistive-technology experience. W3C guidance says to use alt="", with no space between the quotation marks, when an image adds neither information nor an action. That way, people hear what advances the task, not visual elements that only set a mood.
Repeating the same photo can turn information into noise. On a backpack product page, thumbnails that only repeat the main image can be empty when they do not show a different detail. The choice depends on what the page already communicates.
What should I write when an image contains text, such as a promotion or ad?
Readable words inside an image must also reach people who cannot see it. The W3C image tutorial recommends including those words in the alternative; outside of logos, it is often better to present text as real content when the design allows it.
A promotion needs to retain the condition that changes a decision. If an ad says “Free shipping in Bogotá through Friday” and that information is not beside the image, that phrase communicates more than “shipping banner.” On landing pages built around an action, this prevents the offer from disappearing for part of the audience.
How do I describe a chart, infographic, or information-heavy image?
A complex visual needs a short summary and an explanation people can consult. web.dev suggests a brief alternative plus a link or jump to an extended explanation on the same page for charts, maps, and infographics.
Alt text announces the main finding while nearby content supplies the detail. For example, a sales chart can summarize the trend in alt text and present the figures and periods in a table below. Each format then has a clear job.
| Image type | Brief alt text | Extra detail |
|---|---|---|
| Product photo | Deciding feature | Page and variants |
| Promotion | Offer and condition | Page text |
| Chart | Main finding | Table or explanation |
Does alt text help your images’ SEO?
Useful context helps explain an image, but it does not guarantee a ranking. Google asks for informative, contextual alt text and warns that repeated keywords harm the experience and can look like spam. The sentence should describe this image, on this page, for this person.
How an image is published also determines whether search can discover it. Google finds images in the src attribute of an img tag, but it does not index images set as a background with CSS, the code that styles the page. If your site uses a theme or page builder, check how it delivers each image before assuming the alt field solves everything, and watch its weight too, as we explain in how to optimize images for the web.
- Does the sentence convey the information or action the image adds?
- Does it describe this specific version instead of repeating keywords?
- Does a promotion’s visible text also appear in the alternative?
- Does a decorative image use alt="", with no space between quotation marks?
- Does a chart have an extended accessible explanation near the image?
- Is the image published as an img when Google should discover it?
Frequently asked questions about image alt text
Should alt text for an image link describe the image or the action?
When an image is a link, its alternative communicates the destination or action. Google notes that alt text on a linked image acts as anchor text. A magnifying glass that opens search needs to say “Search,” while a thumbnail leading to a product page should identify the product or destination.
Should I start alt text with “image of” or “photo of”?
A description is usually more useful when it starts with relevant content. A screen reader already announces that it is an image, so “Black waterproof backpack” delivers information sooner than “Photo of a black waterproof backpack.” The exception depends on whether the image type adds necessary meaning.
How do I add alt text to an image in Word?
Word lets you write, review, or approve alt text from the image’s own panel. Right-click the photo and choose View Alt Text to open that panel; if Microsoft 365 suggested one automatically, its help says to edit or approve it and, if the image only decorates, mark it as decorative. The Accessibility Checker, on the Review tab, flags images left without text.
Need images that explain what they contribute?
At User Media, we design pages and creative where every image supports the message, accessibility, and your customer’s journey. Let’s talk about your project.
