Image Alt Text

Image alt text (alternative text) is short, descriptive, and relevant to the image's content and surrounding text. It is used to provide context and meaning for users who cannot see an image, including those using screen readers or who have disabled images in their browsers.

Purpose of Alt Text

  • Accessibility: Screen readers use alt text to describe images to visually impaired users, helping them understand the content and context of visuals.
  • SEO: Search engines use alt text to understand image content, improving a webpage’s search engine ranking.
  • Fallback Content: If an image fails to load, the alt text will be displayed in its place.

Key Best Practices

  • Be Descriptive and Specific: Use alt text to accurately describe the image's content and context. For example, instead of "dog," use "Golden Retriever puppy playing in a park".
  • Keep it Concise: Aim for short, impactful descriptions, typically under 125 characters.
  • Avoid Redundancy: Don't start with "image of" or "picture of"; screen readers already identify it as an image.
  • Use Keywords Sparingly: Incorporate relevant keywords but avoid keyword stuffing.
  • Consider Context: The alt text should relate to the surrounding text and the overall purpose of the page.
  • For Decorative Images, Use Empty Alt Text: If an image is purely decorative and doesn't add information, use alt="".
  • Include Text Within Images: If the image contains important text, include that text in the alt text.
  • Check for Spelling Errors: Misspellings can negatively impact user experience and search engine recognition.
  • Don't Repeat Information: Don't duplicate information already present in captions or surrounding text.
  • Optimize for Search Engines: Alt text can improve SEO, so use relevant keywords where appropriate.

Tools

SiteImprove is an automated web accessibility testing tool maintained by Purdue Marketing & Communications and ITAP. The tool scans your website for web accessibility errors, misspellings and broken links. It also offers suggestions on how to make your website more searchable.

The College of Liberal Arts and its department websites are currently in SiteImprove. To get access to the tool, please  contact Purdue Marketing and Communications.