Alt text no more than 100 characters

Definition The text alternative for an image must be no more than 100 characters in length.
  • A text alternative should summarize the purpose of an image as succinctly as possible for people with visual impairments.
  • Overly long text alternatives can reduce usability by increasing the time it takes to read a web page and understand the significance of the included images.
  • An image with a text alternative that is an empty string (e.g. alt="") is ignored by assistive technologies, and indicates that it is being used for purely decorative, spacing or stylistic purposes rather than for meaningful content.
  • HTML4 Legacy Techniques (Recommended)
  • HTML5 and ARIA Techniques (Recommended)
WCAG 2.0 Success Criteria

1.1.1 Non-text Content (Level A, Primary Success Criterion)

Rule Category Images
Scope Element
Target Resources img, area and [role="img"] elements
  • area
  • img
  • A text alternative (e.g. in English and many other Western languages) should describe the purpose of an image as succinctly as possible (preferably with no more than 100 characters).
  • If a text alternative requires more than 100 characters, consider using the aria-describedby, title or longdesc attribute for a longer, more detailed description of the image, along with shortening the text alternative content.
Informational Links