Images & media
Images, icons, charts, video, and audio carry meaning — a logo identifies a brand, a chart reveals a trend, a photo sets a mood, a video demonstrates a task. When that content has no text alternative, the meaning is locked inside pixels and sound and is lost to anyone who can't see the image or hear the audio. A short, accurate text alternative is what turns a picture into something every user can perceive.
Who this affects
- Blind and screen-reader users hear the text alternative instead of
the image. With no alternative, a screen reader may skip the image, announce a raw file
name like
IMG_4821.jpg, or say only “image”. - Low-vision users who magnify the screen or restyle the page rely on text that scales and reflows; text baked into an image blurs when enlarged.
- Users who turn images off — to save data on a slow or metered
connection, or because an image failed to load — see the
alttext in the image's place. - Some users with cognitive disabilities benefit from concise text that names what an image shows, and from captions and transcripts that let them read along at their own pace.
- Deaf and hard-of-hearing users need captions for video and transcripts for audio to reach spoken content.
Standards covered
Lessons in this category map to the following criteria and laws:
Lessons
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Text alternatives for images
Write correct
alttext for informative images, hide decorative ones, replace images of text, and describe complex charts and diagrams.WCAG 2.2 · 1.1.1 A 1.4.5 AA Captions, transcripts & audio description
Captions for video, transcripts for audio, and audio description for key visuals.
Accessible SVG & icons
Hide decorative SVG, name informative icons, and label icon-only controls.
More media lessons coming
Text alternatives are the foundation. Lessons on time-based media — captions for video, transcripts for audio, and audio descriptions for visual-only content (WCAG 1.2.x) — are on the way. Check back as this category fills out.