Term: Alt Tag
Definition: The alt tag, also known as the “alt attribute” or “alt text,” is an HTML attribute applied to the <img> element that provides a text description for an image.
Expanded explanation: The alt tag is essential for improving a website’s accessibility, as it enables screen readers to convey the content of an image to visually impaired users. Additionally, the alt tag helps search engines understand the context and content of the image, contributing to better image indexing and search engine rankings.
Examples of the term in use:
<img src="example-image.jpg" alt="A cute puppy playing with a ball in the park">
Related terms: Image title attribute, image optimisation, accessibility, SEO
Benefits or importance: Image alt tags are crucial for website accessibility, improving the user experience for visually impaired users. They also enhance SEO by providing search engines with context for images, potentially improving rankings in image search results.
Common misconceptions or pitfalls: A common misconception is that the alt tag is optional or only needed for SEO purposes. However, the primary purpose of alt tags is to improve accessibility for visually impaired users. Additionally, keyword stuffing in alt tags can harm SEO, so it’s essential to use descriptive and natural language.
Best practices or tips:
- Write concise and descriptive alt text that accurately describes the image content.
- Avoid keyword stuffing and use relevant keywords naturally within the description.
- Leave the alt text empty (alt=””) for decorative images that don’t convey content or meaning.
Use cases: Alt tags are commonly used on websites to improve accessibility, especially for online stores, news websites, blogs, and image galleries. Digital agencies frequently use alt tags to optimise their clients’ websites for both SEO and accessibility.
Calculation or formula: N/A
Limitations or considerations: Alt tags alone may not fully convey the purpose or meaning of an image for all users, especially if the image contains text, charts, or graphs. In such cases, it’s essential to provide additional context through the surrounding content or other accessibility features.
Comparisons: Image title attributes are another way to provide additional information about an image. However, unlike alt tags, they are not primarily designed for accessibility and may not be read by all screen readers.
Historical context or development: The alt tag was introduced with the HTML 2.0 standard in 1995 to improve accessibility on the web. Its importance has grown over time as web accessibility and search engine optimisation have become increasingly vital aspects of web design and development.
Resources for further learning: