Alt Text
Here's how I actually think about alt text when I'm in the middle of a real project.
Start here
- Clarify the outcome
- Check the live SERP
- Change one thing, then measure
What I'd do first
- Clarify the outcome you need this week
- Check the live SERP for the query
- Change one page, then measure in Search Console
Plain-English take
Alt text is the HTML text description of an image that helps screen readers, appears when an image fails to load, and gives search engines more context about the image.
What I got wrong
- Treating it as a one-off task
- Copying someone else's playbook without checking intent
- Measuring vanity metrics instead of the job-to-be-done
Next step
Quick answers
What is alt text for images?
Alt text (alternative text) is an HTML attribute added to an image tag that provides a text description of the image. It is used by screen readers for accessibility and by search engines for indexing.
How do I write alt text for SEO?
Write alt text that accurately describes the image while naturally including relevant keywords. Avoid keyword stuffing. Keep it concise and descriptive.
What is the difference between alt text and title text?
Alt text describes the image for accessibility and SEO. Title text provides additional information as a tooltip when hovering over the image. They serve different purposes.
Should I use 'image of' in alt text?
No, avoid phrases like 'image of' or 'picture of' because screen readers already announce that an image is present. Focus on describing the content.
Sources
Primary documentation is linked directly. Anything commercial is marked nofollow.
- Google Search Central — Most authoritative source for how Google handles image and on-page SEO signals.
- WebAIM — Widely cited accessibility authority for writing effective alt text.
- W3C WAI — Standards-based guidance on accessible images and alternative text.
Notes from Callum Bennett.