# Alt Text

The descriptive text defined in an image’s HTML alt attribute; essential for accessibility and critical for image SEO and screen readers.

**Alt Text (Alternative Text / Alt Text)** is the text defined in the `alt=""` attribute of an HTML image that describes what the image is about. It has three core functions:

- **Accessibility:** Screen readers read alt text aloud to visually impaired users. It is a core requirement of the WCAG accessibility standard.
- **SEO:** Search engines understand the image’s content from alt text; it is a primary signal for ranking in Google Images.
- **Fallback display:** If the image cannot load, the browser shows the alt text in place of the image.

### Characteristics of good alt text:

- Clearly describes the image (“red running shoe side view”)
- Is written naturally, without keyword stuffing
- Does not exceed 120 characters
- Is left empty for decorative images (`alt=""`)
- Does not begin with the words “image” or “photo” (unnecessary)

**Tip:** On image-heavy pages, auditing alt text can improve both accessibility and traffic from Google Images.