Web Content
How to Write Image Alt Text That Fits the Article
Describe the image’s useful information or function, distinguish diagrams from screenshots, and avoid keyword stuffing.
Alt text is a text alternative for an image. Its wording depends on what the image contributes to the page. The same image can need different treatment in different contexts. Start by deciding whether it conveys information, performs an action, or is decorative. Then write an alternative that supports that role rather than describing every visible detail.
Identify the purpose in this page
Ask what the reader would lose if the image were unavailable. A process diagram may show the relationship between steps. A linked icon may identify an action. A decorative texture may add atmosphere without conveying information. The alternative should serve that purpose. Do not automatically turn the article title into alt text when the image communicates something more specific or serves no informational role.
Describe information rather than appearance alone
For a writing-brief diagram, “A brief connects reader, purpose, evidence, and output” is more useful than “Four green boxes.” If the colors encode a distinction, explain that meaning in the article or alternative. Avoid phrases such as “image of” when they add nothing. Use them when the medium matters, for example distinguishing a screenshot from a conceptual illustration.
Keep important detail in the article
A complex diagram should have a nearby explanation that works without seeing it. A caption can identify its source, context, or conceptual nature. Alt text should not carry an entire tutorial that appears nowhere else on the page. For a chart, describe the meaningful result and provide the underlying data or equivalent explanation where appropriate. Do not present a fictional chart as measured research.
Handle decorative and functional images differently
A purely decorative image can have an empty alternative so it does not add unnecessary content for assistive technology. A functional image should explain the action or destination. A logo linking to the homepage may need wording that identifies the site and destination. Check how the image is actually used, because a decorative asset can become functional when it is placed inside a link or button.
Work through a fictional example
Suppose an article shows a diagram of drafting, structural editing, sentence editing, and final preview. A suitable alternative might summarize that sequence and its review purpose. The caption can say it is an original explanatory diagram. The article should then explain why structural decisions happen before final proofreading. This combination gives the image a useful role without pretending it is a screenshot of a tested editor.
Check the saved markup
Inspect the public image alternative and confirm that the editor did not discard it. Test the page’s meaning with the image unavailable. Avoid repeating the same alternative for every article image just because their branding matches. Topic-specific visuals need topic-specific descriptions. Relevant wording is also clearer than filling the alternative with unrelated search terms.
Frequently asked questions
Should alt text include keywords?
Use accurate words when they describe the image’s purpose. Do not add unrelated terms or repeat a phrase solely for search visibility.
Is a caption the same as alt text?
No. A caption is visible supporting text. An alternative represents the image’s useful information or function when it is not perceived visually.
Continue your workflow
- A Practical Writing Pass for More Accessible Web Content
- A Pre-Publication Checklist for a Useful, Trustworthy Article
Was this guide helpful?
Tell us what needs improving →
Your selection stays on this page. To send feedback to the publication, use our contact form.
Published 28 September 2026 · Text Craft Pro · AI-assisted educational writing. Editorial policy · Suggest a correction