Alt text is a short written description of an image, set with the alt attribute. Screen readers read it aloud, it appears if the image fails to load, and it helps search engines understand images. Meaningful images need it; purely decorative ones should have an empty alt.
The alt attribute makes images accessible and indexable. Good alt text conveys the image's purpose in context; decorative images use an empty alt so screen readers skip them.
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For business owners
Alt text is a rare win-win: it makes your site usable for blind and low-vision visitors, it is a specific legal requirement under accessibility rules, and it helps images rank in search. It costs seconds per image and is one of the most flagged issues in accessibility scans.
How it works (technical)
Use <img src="..." alt="Description">. Describe the image's function in context, not every visual detail. For decorative images that add nothing informational, use alt="" (empty, not missing) so assistive tech skips them. For images that are links or buttons, the alt text should describe the destination or action. Avoid "image of" — screen readers already announce it is an image.
Real-world example
An online shop had product photos with no alt text, so screen-reader users heard only the file name ("IMG_2043.jpg"). Adding concise alt text like "Red leather crossbody bag, front view" made products understandable and improved image search traffic.
Why it matters
Missing alt text is one of the most common accessibility failures and a direct WCAG requirement. It is easy to detect and fix, and it benefits SEO too.
How to fix it
Add descriptive alt text to every meaningful image.
Describe the image's purpose in context, concisely.
Use
alt=""for purely decorative images.For linked images, describe the destination or action.
Re-scan to confirm no meaningful images are missing alt text.
Best practices
Keep it concise and contextual.
Skip "image of" / "picture of" prefixes.
Empty alt for decoration, descriptive alt for content.
Common mistakes
Leaving alt missing entirely (screen readers may read the filename).
Stuffing keywords instead of describing the image.
Writing alt text for decorative images, adding noise.
Frequently asked questions
What about decorative images?
Give them an empty alt attribute (alt="") so screen readers skip them. Do not omit the attribute entirely.
Does alt text help SEO?
Yes — it helps search engines understand and rank images, and supports overall page relevance.
Put this into practice
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