Captcha OCR

Documentation

Captcha OCR API

Send a captcha image and get back the text to type, a confidence score, and a reliable flag that says whether to submit it. Built for numeric, arithmetic and Hindi-number captchas, and it also reads alphanumeric text. Get the answer in the same call (about 25 ms), or submit it and fetch the answer later.

API guide →Endpoints, options, billing, errorsSDKs →11 languages, verified end to endTask API →createTask / getTaskResult endpoints

Quickstart

  1. Sign in with Google or e-mail. New accounts get 5,000 free credits.
  2. Open Dashboard → API keys and create a key. Copy it: it's shown once.
  3. Export it as CAPTCHA_API_KEY and send your first captcha:
curl -s https://captchaocr.allvoraz.com/v1/solve \
  -H "Authorization: Bearer $CAPTCHA_API_KEY" \
  -H 'Content-Type: application/json' \
  -d "{\"image\": \"$(base64 < captcha.png | tr -d '\n')\", \"numeric\": true, \"length\": 6}"

The response:

{
  "text": "482915",        // what to type
  "confidence": 0.99,      // least certain character
  "reliable": true,        // submit only when true
  "engine": "ocr",         // ocr | math | hindi_math
  "raw": "482915",
  "expression": null,      // math only, e.g. "31+6"
  "error": null,           // "invalid_image" when undecodable
  "id": 184467,            // for /v1/report
  "charged": true          // reliable answers cost 1 credit
}

How it works

  • Base URL: https://captchaocr.allvoraz.com. Every endpoint is under /v1.
  • One credit per reliable answer. If reliable is false, or the image can't be decoded, it's free. Fetch a new captcha and try again.
  • Describe the captcha. numeric, uppercase, lowercase and length steer the decoder. math and hindi pick the arithmetic engines. See options.
  • Two ways to call. /v1/solve waits and returns the answer. /v1/submit returns a task id at once; fetch the answer with GET /v1/result/{id} (add ?wait=10 to skip polling). See submit now, fetch later.
  • Batch it with /v1/solve_batch (up to 256 images), or call /v1/solve concurrently. Both are equally fast per image.
  • Wrong answer? POST /v1/report with its id returns the credit.

Next steps

  • API guide: every endpoint, field and error.
  • SDKs: install and use the client for your language.
  • API reference: interactive, with a try-it console.
  • openapi.json: import into Postman, Insomnia or Bruno.