AI Image Captioning - Auto-Describe Images Free

Q: What AI model generates the captions?

This tool uses the ViT-GPT2 image captioning model from Hugging Face, running locally in your browser via Transformers.js. The model (~100MB) is cached after first download.

Q: What can I use image captions for?

Image captions are great for writing alt text for accessibility, describing images for social media, generating metadata for photo libraries, and content creation.

Q: How accurate are the AI captions?

The ViT-GPT2 model provides reasonable descriptions for common subjects like people, objects, and scenes. Complex or abstract images may produce less accurate results.

Q: Are my images private?

Yes. All processing happens locally in your browser using WebAssembly. Your images never leave your device.

Generate automatic AI descriptions for any image. Great for alt text and accessibility. Runs 100% in your browser — no upload, no account, fully private.

No Upload 100% Private Free

Drop your image here

JPG, PNG, or WebP — AI will describe what it sees

How AI Image Captioning Works

Upload Your Image

Select a JPG, PNG, or WebP image. It stays on your device — nothing is uploaded.

AI Analyses the Image

The ViT-GPT2 model analyses visual features and generates a natural language description.

Get Caption & Alt Text

Copy the generated caption or use it directly as an HTML alt text attribute.

Frequently Asked Questions

What can I use AI image captions for?

Writing alt text for web accessibility, describing images for social media, generating metadata for photo libraries, content creation, and making images discoverable for screen readers.

What AI model generates the captions?

The tool uses the ViT-GPT2 image captioning model from Hugging Face, running locally via Transformers.js. The model is ~100 MB and cached after the first download.

Are my images private?

Yes. All processing happens locally using WebAssembly. Your images never leave your device.

How accurate are the AI captions?

The ViT-GPT2 model works well for common subjects like people, animals, objects, and scenes. Abstract or artistic images may produce less specific descriptions.