This guidance currently aligns with the Web Content Accessibility Guidelines (WCAG) 2.1 and is being updated to reflect WCAG 2.2.
Organisations subject to the Web Accessibility Directive or the European Accessibility Act should refer to WCAG 2.2 (W3C.org)(w3.org) (w3.org)(w3.org) (w3.org)(w3.org) (w3.org), as compliance will be required when the revised EN 301 549 standard (PDF)(etsi.org) (etsi.org)(etsi.org) (etsi.org)(etsi.org) (etsi.org) is published in the Official Journal of the European Union in December 2026.
In this section
- All images must have a text equivalent (“Alt text”)
- Provide text equivalents for audio content
- Provide audio descriptions and text equivalents for video content
References for this section
WCAG 2.1
- 1.1.1 Non-text Content (A)
- 1.2.1 Audio-only and Video-only (Pre-recorded) (A)
- 1.2.2 Captions (Pre-recorded) (A)
- 1.2.3 Audio Descriptions or Media Alternative (Pre-recorded) (A)
- 1.2.4 Captions (Live) (A)
- 1.2.5 Audio Description (Pre-recorded) (AA)
EN 301 549 v 2.1.2
- 9.1.1.1 Non-text Content
- 9.1.2.1 Audio-only and Video-only (Pre-recorded)
- 9.1.2.2 Captions (Pre-recorded)
- 9.1.2.3 Audio Descriptions or Media Alternative (Pre-recorded)
- 9.1.2.4 Captions (Live)
- 9.1.2.5 Audio Description (Pre-recorded)
Video
- W3C Perspectives Video - Video Captions
- W3C Understanding Differences in Low Vision Activity - Integrated Audio Description & Transcript
- W3C Perspectives Video - Audio Description Example
- Accessible Images: Bad Alt Text Examples – Web Accessibility Education
Further reading
- WebAIM’s alternative text page
- WebAIM’s complex image tutorial
- 3 questions to Help Decide If an Image Doesn't Need Alt Text
- WAI Decorative Images
- Deafness and the User Experience
- Accessibility according to actual people with disabilities
- Alternate text for background images
- WAI guidance on images
- WAI Alt text Decision Tree
- Text descriptions and emotion rich images
- Writing great alt text: Emotion matters
- Google – Add subtitles and captions