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Image Captioner by PDF Extract API
x402
Image Captioner by PDF Extract API is a paid API for AI agents from image-captioner.pdfextractapi.workers.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-15).
Analyzes an uploaded image and returns a human-readable caption, alt text, descriptive tags, and dominant colors.
Price / call$0.02
Success—
StatusUnknown
How this service works
Generate a caption, alt text, tags, and dominant colors for an image.
Output
The endpoint returns a structured response containing a generated natural-language caption describing the image, alt text suitable for accessibility use, a list of descriptive tags, and the dominant colors present in the image.
Example use cases
Accessibility alt text for web images
“I'm uploading a product photo to my website — can you generate proper alt text and a short caption for it so it's accessible to screen reader users?”
Auto-tagging e-commerce product images
“I have a batch of product images I need to organize — can you analyze this image and give me tags and dominant colors so I can categorize and filter it in my catalog?”
Social media caption generation
“I just took a photo I want to post — can you look at this image and write a caption for it, plus tell me what tags and colors stand out?”
Technical details
Endpoint
POSThttps://image-captioner.pdfextractapi.workers.dev/captionWhen to prefer
Choose this endpoint when you need to enrich image assets with metadata — especially caption text, accessibility alt text, content tags, and color palette — in a single call without setting up your own vision model pipeline. It is well-suited for content management, e-commerce cataloging, and accessibility workflows where you need structured image descriptions quickly and cheaply at $0.02 per image.
Side effects
- Missing or malformed image file returns an error — file field is required
- Unsupported image format may cause processing failure
- Large file sizes may exceed Cloudflare Worker limits and result in a timeout or error
- Invalid body type (not form-data with binary file) causes schema validation failure
- Network timeout if image processing takes too long
Input
Schema · Request body
| Field | Type | Description |
|---|---|---|
| inputrequired | object | |
| output | object |
Tags
x402
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