What is Alt Text?
Definition
Alt text is an HTML attribute that provides a text description of an image, serving both accessibility needs for visually impaired users and helping search engines understand image content.
Why alt text matters
Alt text matters first for accessibility. Screen readers rely on alt text to describe images to visually impaired users, making web content inclusive and usable for everyone.
For SEO, alt text helps search engines understand image content since they cannot 'see' images the way humans do. Descriptive alt text can help images appear in image search results and contributes to the overall topical relevance of a page.
Alt text also provides fallback content when images fail to load, ensuring users still understand what was meant to appear on the page.
Key concepts and types
- •Descriptive accuracy
Alt text should accurately describe what the image shows, not what you wish it showed. - •Conciseness
Effective alt text is typically under 125 characters, conveying essential information without unnecessary words. - •Context relevance
Alt text should consider the image's purpose within the page context, not just describe it in isolation. - •Decorative image handling
Purely decorative images should use empty alt attributes (alt='') so screen readers skip them. - •Keyword integration
Including relevant keywords naturally when they accurately describe the image, without keyword stuffing.
Common misconceptions
- ✕Alt text should be stuffed with keywords for SEO benefit
- ✕Every image needs detailed alt text regardless of purpose
- ✕Alt text and image titles are the same thing
- ✕Alt text should start with 'Image of' or 'Picture of'
- ✕Decorative images need descriptive alt text
Related terms
FAQs
How long should alt text be?
Alt text should typically be under 125 characters. Some screen readers cut off longer descriptions, so focus on conveying the essential information concisely.
Should logos have alt text?
Yes, logos should include alt text with the company or brand name. If the logo links to the homepage, alt text like 'Company Name - Home' provides helpful context.
Does alt text affect rankings directly?
Alt text is a minor ranking factor that primarily helps with image search visibility. Its main value is accessibility and helping search engines understand page content contextually.