Alt text, or alternative text, is a brief description added to an image’s HTML tag. It serves two main purposes: helping visually impaired users understand what an image represents and providing context to search engines for better indexing.
Why Alt Text Matters
Alt text plays a vital role in accessibility and SEO. It ensures your content is inclusive and also improves how search engines interpret and rank your pages.
1. Accessibility for Screen Readers
For users relying on screen readers, alt text describes the image content. This is essential for creating an inclusive web experience, especially for government or education websites where accessibility is a requirement.
2. SEO and Image Search
Alt text allows search engines to understand what an image is about. Properly optimized alt text can improve visibility in Google Image Search and contribute to overall page ranking.
3. Image Loading Issues
If an image fails to load, the alt text appears in its place. This ensures that users still understand the context of the image, even if it’s missing or slow to render.
How to Write Effective Alt Text
- Be descriptive but concise: Focus on the core content of the image.
- Avoid using phrases like “image of” or “picture of”.
- Include target keywords if relevant, but don’t keyword-stuff.
- Consider the image’s function: Is it decorative, informational, or functional?
Example (Informative)
Poor: img alt="photo"
Better: img alt="Chef preparing sushi rolls at a restaurant counter"
Example (Decorative)
If the image is purely decorative, use an empty alt attribute like alt="" to signal screen readers to skip it.
Alt Text Best Practices
- Write unique alt text for each image
- Don’t repeat captions or nearby content
- Use plain language and keep it under 125 characters
- Think about user intent and context
- Always add alt text to buttons or icons with functions (like “Search” or “Submit”)
Final Thoughts
Alt text is a simple but powerful tool that improves both user experience and search engine visibility. Whether you’re running a blog, e-commerce store, or business website, using effective alt text should be part of your SEO and accessibility strategy. By writing thoughtful, descriptive alt text, you’re not only supporting a wider audience but also giving your content a better chance to rank and reach more people.