Alt text for SEO
Alt text is one of the few places where writing for accessibility and writing for search are the same job. Describe the image well for a person, and you have described it well for Google.
Keyword stuffing meter
11 words · keyword appears 4× · 73% of words
Keyword stuffing. Google warns this can make a site look spammy, and it is tiring to listen to.
What Google says
Google Search Central's image SEO guide says alt text is the most important attribute for giving Google information about an image, and that it is combined with computer vision and the content of the page. The same guide warns against filling alt with keywords, which "results in a negative user experience and may cause your site to be seen as spam."
Source: Google Search Central, Google Images best practices.
Where alt text carries SEO weight
- Image search. Alt, file name, surrounding text and page title together decide what queries an image can appear for.
- Linked images. When an image is a link, its alt text acts as the anchor text for the linked page.
- Page relevance. Alt is part of the page's text content, so it can reinforce the topic, gently.
- Product results. Clear product images with accurate alt help shopping surfaces match variants (colour, material).
A keyword rule you can use
Include the keyword once, if it's true of the image. A photo of your ceramic teapot can say "ceramic teapot". A photo of your team on the ceramic teapot page should not. For everything else about image ranking (file names, formats, size, srcset), run the image SEO analyzer.
Alt text is not the only place
Captions are read by more people than alt text, and Google uses nearby text too. Put important words in visible text first, then let alt describe the picture.
Questions people ask
Does alt text help SEO?
Yes. Google's image SEO documentation calls alt text the most important attribute for providing metadata about an image, and uses it together with computer vision and page content to understand the image. It also becomes the anchor text when an image is a link.
Should I put keywords in alt text?
Only when they honestly describe the image. Google warns that filling alt attributes with keywords (keyword stuffing) creates a negative user experience and may cause your site to be seen as spam.
Does alt text help Google Images rankings?
It is one of the main text signals for image search, along with the page title, headings, surrounding text, the file name and structured data.
Is alt text used by AI search engines?
Crawlers that read HTML, including those feeding AI answers, can read alt attributes like any other text on the page. Descriptive alt makes your images understandable to any system that reads text, but no provider publishes exactly how much weight it gets.