What Is Alt Text and How Do You Write It?
Alt text is the short text description attached to an image that screen readers read aloud and search engines use to understand the image. Good alt text describes what the image shows in context, in one plain sentence, and omits phrases like "image of".
The formula
Describe the content, then the function if there is one. A product photo needs the product name and variant. A chart needs its takeaway, not just "chart". A decorative divider needs empty alt, alt="", so screen readers skip it.
Three mistakes to avoid
- Writing "image of logo": screen readers already say "image".
- Stuffing keywords into decorative images.
- Leaving it empty on meaningful images, which fails accessibility and SEO together. 28% of audited pages miss alt text on at least one image.
Check every image on your page free
Run the URL through the On-Page SEO Checker, which lists every image missing or skimping on alt text, alongside the rest of the on-page checks.
Frequently Asked Questions
How long should alt text be?
One clear sentence, under about 125 characters.
Does alt text help Google Images traffic?
Yes, it is a primary signal for image ranking.
Related reading
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