This is the third post in a four-part series on ALT text. Because writing it well (and knowing when not to write it) deserves more than a quick checklist. See part two, The Most Accessible ALT Text Is Sometimes No ALT Text at All.
ALT text is one of the few content elements designed to be read by screen readers, indexed by search engines, and interpreted by AI models. It's also a strategic advantage. When it's treated as a content decision, it shifts from being a literal description to purposeful communication.
Who (or What) Benefits and How?
Screen reader users
Meaning Not Clutter
Screen reader users don’t need a granular description of an image. The most important information they need is why the image is on the page. Writing ALT text with intent communicates the image’s role in the content, whether it reinforces a key point, conveys data, signals emotion, or functions as a control.
For example, Smiling woman at desk is a description. A customer success manager reviewing accessibility audit results is meaningful if that context matters to the story.
Intentional ALT respects the flow
Screen reader users experience webpages linearly, so redundant or overly detailed ALT text can disrupt the reading rhythm. Thoughtful ALT text supports the content's structure and flow. It doesn't include irrelevant details or repeat content from nearby text.
Builds trust
When ALT text consistently conveys the image's purpose, screen reader users will trust they're receiving equivalent information.
At its best, ALT text written with intent ensures that screen reader users receive the same substance, emphasis, and context as sighted users, even when the medium differs.
Search Engines
ALT text is one of the strongest indicators of an image’s purpose on the page. When it’s crafted with intention, it helps search engines grasp the content’s meaning in several important ways:
- It reinforces topical relevance.
Intentional ALT text connects the image with the page’s subject. For example, if a blog post is about accessible navigation and you write ALT text that explains the function of a hamburger menu (instead of just saying “three lines icon”), you’re informing the algorithm of meaningful, keyword-aligned data. Search engines then associate the image with the page and reveal it in relevant queries. - It reduces noise in the content.
Search engines are trained to detect SPAM-like patterns. Generic ALT text can produce such a pattern. Purpose-driven ALT text reads naturally and contextually, which improves content quality and reduces the appearance of SPAM.
NOTE: Keyword-stuffed ALT text fails for both humans and search engines.
- It improves image search performance.
Google Image Search relies heavily on ALT text. When ALT text communicates what the image represents, not just what it looks like, it becomes more discoverable for relevant queries.
For example:- Weak: woman at a computer
- Intentional: Content strategist reviewing website accessibility report in an analytics dashboard.
- It supports semantic indexing.
Major search engines like Google and Bing rely heavily on Natural Language Processing (NLP) to interpret not just keywords but the meaning behind a query by analyzing context, relationships, and user intent, delivering results that actually match what someone is looking for. When there is clear intent, it adds helpful context that supports the page’s overall structure and topic.
AI Models
Context with clarity and intent
AI systems read web content in ways strikingly similar to how screen readers do. The same structural elements that make a site accessible for screen reader users also help AI engage with your content.
Strategic ALT text plays a critical role in how AI interprets and understands your content. It provides AI systems with explicit information about what an image depicts, why it matters, and how it relates to the surrounding topic. That structured clarity helps models map relationships, reinforce themes, and reduce unintended biases.
Take this comparison for example.
- Weak ALT text: Image of a woman at a desk.
- ALT text with intention: Customer support specialist reviewing accessibility scan results on a laptop.
The intentional ALT text tells AI what’s happening, why it matters, and very importantly, the domain context (accessibility, analytics, work environment)
That richer pairing helps models better understand how visuals relate to the page's main idea.
Improves multimodal alignment
Alignment in multimodal machine learning is crucial for synchronizing and correlating data from different modalities......ensuring that these diverse forms of data can be effectively integrated and interpreted. ~ Understanding Everything About Alignment in Multimodal Machine Learning: An Intuitive Guide, Jash Pramod Kahar
AI models don't see images the way humans do; they interpret patterns, language, and relationships. When ALT text clearly reflects an image's purpose, its function on the page, its emotional tone, and its relationship to the surrounding content, it becomes context.
That context tells the AI not just what's in the image but also how it fits into the page's narrative, improving content associations. In other words, intentional ALT text helps AI move from surface recognition to meaningful understanding. And that strengthens multimodal alignment.
For example:
- A button image labeled Submit
vs. - ALT text: Search button with a magnifying glass icon.
The ALT text tells the AI the icon’s function, not just its appearance. That teaches models how visuals work in real-world interfaces, improving areas such as UI interpretation, automation, and accessibility tooling.
Reduces bias and lazy pattern learning
ALT text that’s vague, like a man smiling, a team meeting, or a city skyline, only scratches the surface of what’s happening in an image. That vagueness can unintentionally reinforce shallow assumptions about people, places, or situations because it doesn’t explain why the image matters.
Intentional ALT text answers questions like:
- What is the man doing or representing in this context?
- Why is the meeting important?
- Is the skyline just decoration, or is it directly related to the page’s topic?
By including these details, your ALT text can give the image real meaning, help avoid misleading or overly simplistic interpretations, and encourage a more accurate, thoughtful understanding of the content. This ensures that anyone relying on the text, whether human or system, gets the full picture (😉) rather than a stripped-down context.
Teaches prioritization
When you decide:
- This image is decorative, so it should have an empty ALT tag.
- This image is functional, so the ALT text should describe its action.
- This image is informative, so the ALT text should convey its message.
You’re not treating the ALT text (or the absence of it) as a technical task; you are making an editorial decision. You’re putting purpose and context front and center, training AI to evaluate what actually matters instead of defaulting to surface-level descriptions. That gives AI models a better sense of when an image is meaningful and when it’s merely decorative, giving the image the appropriate weight in interpreting the page.
Making that distinction also sharpens context mapping. Meaningful images reinforce the topic, relationships, and intent of the surrounding content. Decorative elements don’t. When a model can separate the two, AI users receive better summaries and more relevant content retrieval.
There is also an impact on training data. When models repeatedly encounter visuals intentionally marked as decorative, they learn not to assign meaning where none exists. That reduces bias toward aesthetic trends and keeps learning focused on substance.
And finally, accessibility alignment improves. As stated in the Screen Readers section of this post, the same practices that clarify intent for assistive technology users also clarify intent for AI systems. In this case, accessibility best practices directly strengthen machine understanding.
The Big Picture
ALT text is more than a description. ALT text is an editorial decision. Written with intent, it works on multiple levels: it supports screen reader users, reinforces the structure and meaning of your content for search, and strengthens AI understanding of your content.
Prioritizing meaning and intent in your ALT text is about conveying clarity and purpose. ALT text should communicate relevance, meaning, and context, making your content readable for humans and intelligible to machines. A few thoughtful words that provide a big impact.
Resources
- SEO & AEO: Two Strategies, One Goal
- When AI Reads Like a Screen Reader
- ALT Text and Answer Engine Optimization
A human author creates the DubBlog posts. The AI tools Gemini and ChatGPT are sometimes used to brainstorm topic ideas, generate blog post outlines, and rephrase portions of content. Our marketing team carefully reviews all final drafts for accuracy and authenticity. The opinions and perspectives expressed remain the sole responsibility of the human author.
