Definition
Alt text (alternative text) is a short descriptive attribute added to an image in HTML. This the visually impaired and search engines to understand the content of the image. It appears in the <img> tag as alt=”description of the image”. Alt text is crucial for web accessibility, as screen readers use it to describe images to users who cannot see them. Search engines can index the image improving Search Engine Optimization (SEO). Also, the alt text displays if an image fails to load.
Why It Matters
Alt text improves web accessibility, ensuring that visually impaired people using screen readers will understand the image’s meaning. Search engines depend on alt text to index images properly, helping websites rank higher in Google Image Search and improving overall SEO. It enhances user experience by providing context when images don’t load due to slow internet connections or technical issues. Properly written alt text can drive organic traffic from image searches, increasing a website’s visibility. Without alt text, websites may lose accessibility compliance and miss SEO opportunities.
How It’s Used
Website owners add alt text to images to improve accessibility and search rankings. Bloggers use descriptive alt text to ensure their images appear in search results and reach a wider audience. E-commerce websites write detailed alt text for product images to help customers find products through Google Image Search. News websites and media outlets include alt text for featured images to ensure accessibility compliance. Developers and designers use automated tools to check for missing alt text and improve website usability.
Example in Action
A travel blogger uploads a photo of the Eiffel Tower at sunset. Instead of using generic alt text like “Eiffel Tower”, they write:
<img src=”eiffel-tower.jpg” alt=”Eiffel Tower at sunset with orange and purple sky”>
This descriptive alt text improves the image’s chances of appearing in search results for “Eiffel Tower sunset”, while also making it accessible to visually impaired users.
Common Questions and Answers
- What is alt text used for?
- Alt text is used for web accessibility and SEO, helping screen readers and search engines understand image content.
- How do I write good alt text?
- Be descriptive but concise, avoiding generic phrases like “image of” or “picture of.”
- Does alt text affect SEO?
- Yes, properly optimized alt text helps images rank in Google Image Search, improving website traffic.
- Should every image have alt text?
- Essential images (like product photos or infographics) should have alt text, but decorative images can have an empty alt=”” attribute.
- How long should alt text be?
- Keep it under 125 characters for optimal readability by screen readers.
Unusual Facts
- Google cannot “see” images, so it relies on alt text and AI to understand them.
- Websites that include optimized alt text on images see an increase in organic traffic from Google Image Search.
- Alt text has been required by web accessibility guidelines (WCAG) for years, ensuring equal access for all users.
- Decorative images should have empty alt attributes (alt=””) to stop screen readers from detecting unnecessary descriptions.
- AI-powered tools like Google Lens use alt text and metadata to recognize and categorize images.
Tips and Tricks
- Be specific—describe what’s in the image with relevant details.
- Use keywords naturally to improve SEO without keyword stuffing.
- Avoid using “image of” or “picture of”—screen readers already recognize it as an image.
- For linked images, the alt text should describe the destination, not just the image itself.
- Test alt text with screen readers to ensure it provides a good user experience.
True Facts Beginners Often Get Wrong
- Alt text is not a caption—it should describe the image for accessibility, not add commentary.
- Leaving alt text blank for important images reduces both accessibility and SEO potential.
- Stuffing alt text with keywords can result in Google penalties and poor readability.
- Alt text should describe the image meaningfully, not just list objects in the picture.
- Alt text does not affect how an image looks on a page—it is only used for accessibility and search indexing.
Related Terms
[SEO] [Web Accessibility] [Image Optimization] [Screen Readers] [Google Image Search]