Alt Text
Alt text (alternative text) is an HTML attribute added to image tags that describes the image content for accessibility and search engine understanding.
§ 1 Definition
Alt text serves two critical functions. First, it makes images accessible to visually impaired users who rely on screen readers. Second, it helps search engines understand what an image depicts, since they cannot 'see' images the way humans do. Alt text is a minor ranking factor for image search and a supporting signal for page relevance.
§ 2 Writing Good Alt Text
Describe the image accurately and concisely. Include the target keyword only if it naturally fits the description. Do not keyword stuff. If the image is decorative rather than informative (a background pattern, a spacer), use `alt=""` (empty alt) so screen readers skip it.
§ 3 Common Alt Text Mistakes
The biggest error is omitting alt text entirely. The second is using alt text as a keyword dumping ground. 'Red sports car driving on mountain road' is good alt text. 'Cheap cars Milwaukee Wisconsin best deals' is not. It confuses search engines and annoys screen readers.
§ 4 Note
§ 5 In code
<!-- Good alt text -->
<img src="sports-car.jpg" alt="Red sports car driving on a mountain road">
<!-- Bad alt text (keyword stuffing) -->
<img src="sports-car.jpg" alt="cheap cars used cars Milwaukee Wisconsin best car deals">
<!-- Decorative image -->
<img src="divider-line.png" alt="">- Alt text improves accessibility AND SEO
- Describe the image naturally; do not keyword stuff
- Use empty alt (alt="") for decorative images
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Get in touchAlt text (alternative text) is an HTML attribute added to image tags that describes the image content for accessibility and search engine understanding.
Category: SEO
Author: Atomic Glue SEO & GEO Team
## Definition
Alt text serves two critical functions. First, it makes images accessible to visually impaired users who rely on screen readers. Second, it helps search engines understand what an image depicts, since they cannot 'see' images the way humans do. Alt text is a minor ranking factor for image search and a supporting signal for page relevance.
## Writing Good Alt Text
Describe the image accurately and concisely. Include the target keyword only if it naturally fits the description. Do not keyword stuff. If the image is decorative rather than informative (a background pattern, a spacer), use `alt=""` (empty alt) so screen readers skip it.
## Common Alt Text Mistakes
The biggest error is omitting alt text entirely. The second is using alt text as a keyword dumping ground. 'Red sports car driving on mountain road' is good alt text. 'Cheap cars Milwaukee Wisconsin best deals' is not. It confuses search engines and annoys screen readers.
## Note
Alt text is often confused with image title attributes (title text). Title text appears on hover as a tooltip. Alt text is for accessibility and SEO. Only alt text is a ranking signal.
## In code
<!-- Good alt text --> <img src="sports-car.jpg" alt="Red sports car driving on a mountain road"> <!-- Bad alt text (keyword stuffing) --> <img src="sports-car.jpg" alt="cheap cars used cars Milwaukee Wisconsin best car deals"> <!-- Decorative image --> <img src="divider-line.png" alt="">
## Key takeaways
- Alt text improves accessibility AND SEO
- Describe the image naturally; do not keyword stuff
- Use empty alt (alt="") for decorative images
## Related entries
- [On-Page SEO](atomicglue.co/glossary/on-page-seo)
- [Technical SEO](atomicglue.co/glossary/technical-seo)
Last updated June 2026. Permalink: atomicglue.co/glossary/alt-text-seo