Alt Text (Alternative Text / Alt Metin) is the text defined in an HTML image’s alt="" attribute that describes what the image is about. It has three main functions:
- Accessibility: Screen readers read the alt text to visually impaired users. It is a core requirement of the WCAG accessibility standard.
- SEO: Search engines understand the image’s content from the 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 (“side view of red running shoe”)
- Written naturally in Turkish, without keyword stuffing
- Does not exceed 120 characters
- 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.