How to Write SEO Alt Text for Images (With Real Examples)
Alt text is both an accessibility requirement and a genuine Google Image Search ranking signal. Here's how to write it well, with examples.
What alt text actually does
Alt text (the alt attribute on an <img> tag) serves two distinct purposes: it's read aloud by screen readers for visually impaired visitors, and it's one of the strongest textual signals Google has for understanding what an image actually shows — since Google can't "see" an image the way a human does, at least not with full confidence. Both purposes reward the same thing: a clear, accurate, specific description.
The difference between good and bad alt text
Bad: alt="image1.jpg" — tells Google and screen readers nothing.
Bad (keyword stuffed): alt="shoes running shoes buy running shoes cheap running shoes sale" — this reads as spam to both Google and a screen reader user, and can actively hurt rankings.
Good: alt="Women's red running shoes, side view, on a white background" — specific, accurate, and naturally includes relevant terms (color, product type, angle) without stuffing.
A practical framework for writing alt text
Ask yourself: if I were describing this image over the phone to someone who couldn't see it, what would I say? That description — trimmed to the essential details — is almost always good alt text.
For product photos specifically, a reliable pattern is: [color/material] + [product name] + [distinguishing detail].
Real examples by category
| Image | Weak alt text | Strong alt text |
|---|---|---|
| Product listing photo | "product.jpg" | "Navy blue canvas tote bag with leather handles, front view" |
| Blog post header | "background removal" | "Before and after comparison of a coffee mug with its background removed" |
| Team photo | "team" | "UtilPix founding team at their first office in 2026" |
| Infographic | "chart" | "Bar chart comparing WebP and JPG file sizes at equal visual quality" |
| Decorative image | "line" | alt="" (empty, intentionally — see below) |
When to use empty alt text on purpose
Not every image needs a description. Purely decorative images — a background texture, a divider line, an icon that's redundant with adjacent text — should use alt="" (an empty string, not a missing attribute). This tells screen readers to skip the image entirely rather than reading out something meaningless, and it signals to Google that the image isn't meant to carry semantic weight.
Common mistakes
- Repeating the surrounding caption word-for-word — alt text should add information, not duplicate the visible caption exactly.
- Starting with "image of" or "picture of" — screen readers already announce that it's an image; adding it to the text is redundant.
- Leaving alt text blank on meaningful images — the single most common mistake, especially on product photos uploaded in bulk without review.
- Keyword stuffing — describing an image with an unnatural list of search terms rather than what it actually shows.
Frequently asked questions
Does alt text actually help rankings, or is it just accessibility? Both — Google explicitly uses alt text as an image-understanding signal, and it can help a page rank in Google Image Search specifically, which is a meaningful traffic source for visual products.
How long should alt text be? Long enough to be accurately descriptive, short enough to stay useful — a sentence or a fragment, not a paragraph. Roughly 8-15 words is a reasonable target for most product photos.
Do I need alt text on every single image? Every meaningful image, yes. Purely decorative images should get empty alt text (alt="") rather than being skipped entirely.
Related tools
Generating accurate alt text for a large catalog by hand doesn't scale — the AI Caption Generator drafts alt text (along with titles and descriptions) as a starting point you edit rather than write from scratch.
Try AI Image Caption Generator
Generate titles, descriptions, and alt text