Alt text is one of the simplest ways to improve both website accessibility and on-page SEO. When written well, it helps people using screen readers understand the purpose of an image, and it gives search engines useful context about the content on the page.
But writing effective alt text is not about stuffing keywords into every image. Good alt text is specific, useful, and tied to the image’s role on the page. In this guide, we’ll explain how to write alt text, when to use it, when to leave it empty, and what strong examples look like in practice.
Alt text, short for alternative text, is a written description added to an image in HTML. Its main purpose is accessibility: if someone cannot see the image, assistive technology can read the alt text aloud.
Alt text also matters for SEO because it helps search engines better understand image content and how that image relates to the surrounding page. That said, accessibility should come first. If the alt text is genuinely helpful for people, it is usually also better for search engines.
For digital teams, alt text is part of a broader website accessibility compliance effort. It fits into the same quality and governance process as other accessibility work, including audits, fixes, and ongoing monitoring.
The best alt text explains what a user needs to know about the image in context. Sometimes that means describing what is visible. Other times, it means describing the function or message of the image.
For example, if an image shows a button that takes users to a demo page, the alt text should focus on the action or destination, not only the colors or layout.
Alt text should be clear and direct. Most images do not need a long explanation. A short, accurate description is usually better than a vague or overly detailed one.
Instead of writing something broad like “image” or “photo,” describe what makes the image relevant on that page.
If your target keyword genuinely reflects the image and the page topic, it can appear in alt text naturally. But forcing keywords into every image creates a poor experience for screen reader users and does not improve quality.
For example, on a page about how to write alt text, an image showing a CMS image settings panel could use alt text such as “CMS field for adding alt text to an image.” That is useful, natural, and relevant.
If the same information already appears in a caption, heading, or surrounding paragraph, the alt text does not need to duplicate it exactly. The goal is to add value, not repeat content unnecessarily.
Not every image needs a written description. If an image is purely decorative and adds no meaning, use empty alt text so assistive technologies can skip it. This helps reduce noise for users who rely on screen readers.
Decorative backgrounds, abstract dividers, and purely stylistic icons often fall into this category.
If you are unsure where to start, use this quick approach:
In many cases, the right question is not “What does this image look like?” but “What does this image do here?”
Image: A screenshot of a website accessibility dashboard showing issues and fixes.
Bad alt text: “dashboard”
Better alt text: “Website accessibility dashboard showing detected issues and recommended fixes”
The improved version gives actual context and explains why the image matters.
Image: A clickable logo that returns users to the homepage.
Bad alt text: “company logo blue and green”
Better alt text: “Corpowid homepage”
Because the image functions as a link, the alt text should reflect the destination or function.
Image: A background pattern used behind a hero section.
Bad alt text: “abstract curved background design”
Better alt text: Empty alt text
If the image adds no informational value, it should usually be skipped by assistive technology.
Image: A photo of a compliance team reviewing website issues in a meeting.
Bad alt text: “people in office”
Better alt text: “Compliance team reviewing website accessibility issues in a meeting”
The better version reflects the context of the page and the image’s relevance.
Image: A screenshot of a consent banner settings panel.
Bad alt text: “settings”
Better alt text: “Cookie consent settings panel for managing website privacy controls”
This gives both accessibility value and meaningful page context.
Writing alt text like “how to write alt text accessibility SEO alt text example” is not helpful to users. It reads unnaturally and weakens the user experience.
Screen readers already announce images, so phrases like “image of” or “picture of” are often unnecessary. Use that space for the actual description instead.
When every visual element has descriptive alt text, screen reader users may have to listen to unnecessary content. Decorative images should usually have empty alt text.
Terms like “graphic,” “photo,” or “icon” are rarely enough on their own. They do not tell the user what matters about the image.
The same image may need different alt text depending on where it appears. A chart, screenshot, or product image should be described based on its role in that specific page.
Alt text is a foundational part of accessible content publishing. It helps support inclusive user experiences and is one of the many details teams need to manage consistently across websites, landing pages, blogs, and product content.
For organizations working toward WCAG 2.2, ADA, EAA, or broader digital compliance readiness, alt text should be treated as part of an ongoing process rather than a one-time fix. That means combining content standards, technical checks, and regular monitoring.
As accessibility workloads grow, teams often need more than manual reviews alone. Corpowid focuses on unifying accessibility, cookie consent, and legal compliance in one AI platform, helping teams audit, fix, and monitor digital compliance needs from a single place. If you are also exploring how automation can reduce repetitive accessibility work, see AI Agents Are Here: How Autonomous AI Will Quietly Take Over Your Accessibility To-Do List.
Alt text can help search engines understand image content and page relevance, but it is not a shortcut to rankings. It works best as part of a broader content and technical quality strategy.
Good alt text can support image search visibility and reinforce topical relevance. However, it cannot compensate for weak page structure, thin content, or poor technical performance.
That is why accessibility and SEO often work best together. A site that is easier to understand, navigate, and maintain is usually stronger for users and search engines alike.
Document how your team handles informative, functional, and decorative images. A shared standard reduces inconsistency across pages and contributors.
Do not leave alt text as an afterthought. Include it in content creation, design handoff, and QA processes so it is handled before publication.
Many alt text issues come from repeated components, CMS defaults, or design patterns. Standardizing these areas can improve quality across many pages at once.
Automated tools can help identify missing alt text and other recurring accessibility issues, while human review is still needed to judge quality and context.
For teams looking at digital compliance more broadly, this kind of workflow thinking also applies to consent and privacy controls. You can see a related example in How to Run a Cookie Audit on Your Website in 5 Steps.
Some images contain complex information that cannot be captured in a short alt attribute alone. Charts, infographics, and detailed diagrams may need supporting text in the surrounding content so all users can access the same information.
In those cases, alt text should briefly identify the image, while the page itself provides the fuller explanation.
If you want to know how to write alt text well, the core rule is simple: write for people first. Describe the image in a way that helps someone who cannot see it understand its purpose on the page.
When alt text is useful, concise, and context-aware, it improves accessibility and supports SEO at the same time. For digital teams, that makes it one of the highest-value small improvements you can apply across a website.
And when alt text is part of a larger accessibility and compliance workflow, it becomes easier to maintain quality consistently as your site grows.
No. Informative and functional images should have alt text, while decorative images should usually use empty alt text so screen readers can ignore them.
It should be as short as possible while still being clear and useful. Most alt text works best as a brief phrase or sentence.
Yes, it can help search engines understand image content and page relevance. But it should be written primarily for accessibility, not keyword stuffing.
Alt text is mainly for accessibility and is read by assistive technologies when needed. A caption is visible on the page and is meant for all users.
For functional images, describe the action or destination. Focus on what the image does rather than how it looks.
Corpowid has been recognized by Gartner, a leading global research and advisory firm, for our innovation and performance in digital accessibility. These badges reflect our commitment to creating inclusive, AI-powered web experiences.
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