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InstantTools
Cipher · SEO & AI Visibility

Free Alt Text Generator

Upload any image and get three length-variant alt text descriptions — short for quick captions, medium for standard use, and long for screen readers.

Uses cloud AIUnlike most InstantTools, this tool uses a secure cloud AI model: the content you submit is sent to our AI provider for processing and is not stored. Prefer fully local? Try the in-browser AI tools.
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Drag & drop or click to upload
JPEG, PNG, WebP, GIF · max 4MB

🔒 Your image is sent securely to generate alt text and is not stored or used for training.

Why alt text matters for SEO and accessibility

Alt text (the alt attribute on HTML img elements) serves two critical purposes: accessibility for users who cannot see images, and context for search engines that cannot visually parse them. Screen reader software reads alt text aloud to blind and low-vision users — a missing or poorly written alt attribute leaves a meaningful gap in the page's content for those users.

From an SEO perspective, every image without alt text is a missed opportunity. Google Images is the second largest search engine in the world. Images with descriptive alt text that matches the surrounding content rank in image search and can drive significant referral traffic. For product images, chart graphics, and infographics, alt text is often the primary signal Google uses to understand what the visual is showing.

The WCAG (Web Content Accessibility Guidelines) specification distinguishes between different image types. Informative images need descriptive alt text. Decorative images should have an empty alt attribute (alt=""). Functional images (like buttons with icons) need alt text that describes the function, not the image. This tool generates descriptive alt text — suitable for informative images like product photos, illustrations, screenshots, and infographics.

For AI search engines, images with good alt text are more indexable and citable. When Perplexity or Google's AI Overviews summarise a page that contains a chart or infographic, the alt text is often what the model uses to understand and attribute the visual data. A vague "chart.png" provides nothing; a descriptive alt text like "Bar chart showing year-over-year revenue growth from 2020 to 2024" gives the model exactly what it needs.