ALT text is a written description added to images in HTML, improving accessibility and helping search engines understand visual content.
Also known as “alternative text,” ALT text appears in an image’s HTML code and serves two main purposes:
- It provides a description for users who rely on screen readers.
- It helps search engines understand what the image is about for indexing and SEO.
Why It Matters in SEO:
Search engines cannot “see” images the way humans do. ALT text provides context about the image, allowing search engines like Google to index it properly. Well-written ALT text can help your images rank in image search results and improve overall page relevance.
ALT text is also a critical component for meeting accessibility standards, ensuring your website is usable by people with disabilities.
Characteristics of Good ALT Text:
- Descriptive: Clearly describes the image content and its function on the page.
- Concise: Typically under 125 characters.
- Relevant: Matches the surrounding content and supports the page’s topic.
- Keyword-Aware: Includes relevant keywords naturally, without stuffing.
Common Mistakes:
- Leaving ALT text empty for important images.
- Keyword stuffing (repeating keywords unnecessarily).
- Using vague descriptions like “image” or “picture.”
- Adding ALT text to purely decorative images that don’t convey content.
Best Practices:
- Write ALT text as if you’re describing the image to someone who can’t see it.
- Include a target keyword only when it fits naturally.
- Leave ALT text empty for decorative elements using
alt="". - Make sure every informative image has a unique, relevant ALT description.
Example:
For an image showing a person typing on a laptop for a blog post about remote work, good ALT text might be:
ALT Text: “Remote worker typing on laptop at home desk.”
This tells both search engines and users what the image conveys and aligns with the topic of the content.
