Alternative Text
Alternative text explains an image's useful meaning when someone cannot see the image. It should match the image's job on that page.
Another example
A weather chart says, “Rain chance is highest at 70% at 16:00.” A decorative cloud texture uses an empty alt value. A linked logo names its destination instead of describing its pixels.
Main parts
- 01Purpose in context
- 02Concise equivalent
- 03Complex-data fallback
Use it when
Describe what the image means in its page context. Give complex charts or diagrams the same data in another form.
Do not use it when
Do not start with “image of,” repeat the caption, or describe decoration that adds no information.
Name used in code
img alt, accessible name, or adjacent long-form equivalent Before you ship
Before release, check the page structure, keyboard access, visible focus, contrast, and zoom. Also check loading, empty, error, success, cancel, and reduced-motion states.
Outcome: Use Alternative Text to solve this user need without losing the current context. User context: A weather chart says, “Rain chance is highest at 70% at 16:00.” A decorative cloud texture uses an empty alt value. A linked logo names its destination instead of describing its pixels. Recommended pattern: Alternative Text. Why it fits: Describe what the image means in its page context. Give complex charts or diagrams the same data in another form. Do not use it when: Do not start with “image of,” repeat the caption, or describe decoration that adds no information. Product requirements: Define the default, loading, empty, error, success, and recovery states. Keep user input. Give clear feedback after every action. Accessibility and resilience: Use semantic HTML, full keyboard access, and visible focus. Make the layout work when zoomed and support reduced motion. Follow the project’s current rules. Do not add a new UI library unless the project already uses it. Acceptance criteria: The main task works with keyboard only and at 320px width. Focus and status changes are announced. Check loading, failure, retry, cancel, and reduced-motion paths. Evidence and limits (evidence boundary): The standard covers only the listed scope. It does not choose the visual style, product decision, or Vibulary example. Unknowns to confirm: Product wording, data source, analytics events, supported devices and languages, and platform limits.
Check this request
Review the current use of Alternative Text. Definition: Alternative text explains an image's useful meaning when someone cannot see the image. It should match the image's job on that page. Release checks: Before release, check the page structure, keyboard access, visible focus, contrast, and zoom. Also check loading, empty, error, success, cancel, and reduced-motion states. Before changing code, report the evidence you found, gaps, severity, and the smallest safe fix.