> ## Documentation Index
> Fetch the complete documentation index at: https://www.alttextlab.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Best practices

> Guidelines for writing and reviewing effective alt text.

Effective alt text serves two purposes: it makes images accessible to people using screen readers, and it helps search engines understand your visual content. These guidelines apply whether you're writing alt text manually or reviewing AI-generated output.

## Writing alt text

### Be informative, not exhaustive

Focus on the information that matters. Good alt text conveys what the image communicates — not every visual detail.

**Do:** *A woman holding a reusable coffee cup in a park*

**Avoid:** *A smiling young woman with long brown hair wearing a green jacket holding a white reusable coffee cup while standing near trees in a sunny park*

### Skip "image of" and "photo of"

Screen readers already announce that an element is an image. Prefixes like "image of" or "photo of" add length without value.

### Keep language accessible

Straightforward vocabulary and simple sentence structure work for everyone, including screen reader users. Avoid jargon unless it's meaningful to your audience.

## Match the context

Alt text should reflect why the image is on the page. The same photo needs different alt text depending on where it appears.

* **Product pages** — include product type, color, key attributes, and angle/positioning. *Example: Ergonomic office chair in black mesh, angled three-quarter view*
* **Editorial content** — convey the emotional or thematic significance of the image rather than a literal description
* **Data visualizations** — describe the trend or conclusion, not just the visual structure. *Example: Bar chart showing 40% revenue growth from Q1 to Q4 2024*

## SEO and AEO considerations

Well-written alt text improves both traditional search rankings and visibility in AI-generated answers (Google AI Overviews, Perplexity, ChatGPT with browsing). The same principles apply to both.

### Use keywords naturally

Keywords that appear naturally in a description improve discoverability. Forced keyword insertion degrades readability and provides no benefit.

**Do:** *Ergonomic office chair with lumbar support in black mesh*

**Avoid:** *Office chair ergonomic lumbar support buy black mesh chair SEO*

### Write for meaning, not just metadata

Answer engines reward alt text that captures the actual significance of an image. An image illustrating a concept should have alt text that names the concept, using terminology consistent with the surrounding page content.

**Do:** *Diagram showing the three-stage customer onboarding flow: sign-up, verification, first session*

**Avoid:** *Diagram with arrows and boxes*

<Note>
  Google recommends writing alt text for users first, not search engines. See [Google's image SEO best practices](https://developers.google.com/search/docs/appearance/google-images) for more.
</Note>

## Standards and resources

* [WCAG 2.2 — SC 1.1.1 Non-text Content (Level A)](https://www.w3.org/TR/WCAG22/#non-text-content)
* [W3C WAI — Images Tutorial](https://www.w3.org/WAI/tutorials/images/)
* [W3C WAI — Alt Text Decision Tree](https://www.w3.org/WAI/tutorials/images/decision-tree/)
* [WebAIM — Alternative Text](https://webaim.org/techniques/alttext/)
* [Google — Image SEO best practices](https://developers.google.com/search/docs/appearance/google-images)