What Is Alt Text?
Alt text (alternative text) is the text placed within the alt attribute of an HTML <img> tag. It serves two primary purposes: providing a text alternative for visually impaired users using screen readers, and helping search engines understand image content for indexing in image search. Example: <img src="seo-chart.png" alt="Bar chart showing organic traffic growth from 10K to 50K monthly visits in 2024">
Why Alt Text Matters
Alt text is essential for web accessibility (WCAG compliance) and image SEO. Google Images drives significant traffic for many websites, and alt text is the primary signal Google uses to understand what an image depicts. Pages with descriptive alt text also rank better for image-related searches. Missing alt text is both an accessibility violation and a missed SEO opportunity.
How to Write Good Alt Text
Describe the image accurately and specifically. Include relevant keywords naturally — don't keyword stuff. Keep alt text under 125 characters. Don't start with "Image of" or "Picture of" — screen readers already announce it's an image. Use empty alt (alt="") for purely decorative images. Audit site-wide alt text coverage with CrawlBeast.
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