About this tool
What is the Alt Text Generator?
The ReelStack Alt Text Generator takes any image and produces three accessibility-grade text variants powered by Gemini 3 Flash vision: a short alt attribute (under 125 characters, WCAG 2.2 compliant), a detailed long description (suitable for aria-describedby), and an SEO-friendly caption optimized for image-search.
Built to fix the most common accessibility failure on the web — missing or lazy alt text. The model is prompted to avoid the cliché "image of" / "picture of" prefixes (which screen readers already announce) and to describe what's contextually meaningful rather than mechanically listing every visible element. Run it on portfolio photos, blog headers, product shots, or AI-generated stills before publishing.
Cheap to run on our side (Gemini 3 Flash via Straico) and free for you — 20/hour unauthenticated, 100/day signed in.
FAQ · ALT TEXT GENERATOR
Questions about the Alt Text Generator
What's the difference between alt text and a caption?
Alt text is a short description (≤125 chars) read by screen readers and shown when an image fails to load — it's an accessibility feature. A caption is visible to all users and adds context. We generate both: short alt for the <img alt='...'> attribute, plus a longer SEO caption for visible figure captions or image-search descriptions.
Is it WCAG compliant?
Yes. Output follows WCAG 2.2 Success Criterion 1.1.1 (Non-text Content). Short alt under 125 chars (the screen-reader-friendly limit), no redundant 'image of' prefix, no critical info locked in the image alone. Long descriptions for complex images use semantic phrasing suitable for aria-describedby.
Does it work on AI-generated images?
Yes. The vision model treats AI-generated stills the same as photos — it describes what it sees. Useful for AI filmmakers shipping image work who still need accessible alt text on their portfolio pages.
What languages are supported?
English by default. Pick from 15+ languages in the settings — the model writes the alt text natively in the target language, not a machine translation of English. Includes Spanish, French, German, Japanese, Korean, Mandarin, Filipino, and more.
Is the image stored or used for training?
No. The image is sent to Gemini 3 Flash for vision analysis and dropped immediately after. Straico (the API gateway) and Google both have no-training-on-API-inputs policies. We don't keep a copy on ReelStack's servers.