Image to Text solver API

Solve request#

Solving Image to Text is a single synchronous call. You post one task object and the response carries the finished solution — no task id to store, nothing to poll for.

The connection is held open for the whole solve. Set a client timeout that covers it — the default socket timeout in most HTTP libraries is shorter than the work. If holding a connection that long does not suit your worker fleet, the same task goes to /v1/createTask and you collect it from /v1/checkTask instead.

When to use it#

• Legacy login and registration forms with a distorted-text captcha
• Government, school and utility portals that still use image codes
• Forms that ask for a sum or a missing number in a sequence

Task object structure#

These fields go inside task. The envelope around it — clientKey and the optional softId — is the same for every type and is described in the API reference.

Example payload#

The whole body, assembled from the table above — copy it formatted to read, or on one line to paste straight into a terminal or a REST client. The values are placeholders: swap the key for your own and the URL and site key for the page you are solving.

{
  "clientKey": "void_a1b2c3d4e5f60718293a4b5c6d7e8f90",
  "task": {
    "type": "ImageToTextTask",
    "body": "iVBORw0KGgoAAAANSUhEUgAA…"
  }
}

Example request#

The smallest thing that gets a token back, in your language. Python and Node.js use the official client (pip install voidcaptcha, npm install voidcaptcha); every other language makes the HTTP call its standard library already has. The complete version, with the key read from the environment and the error envelope checked, is in Sample code at the bottom of this page.

Language choice is remembered across the whole site, so switching here carries to every other sample in the docs.

# pip install voidcaptcha
from voidcaptcha import VoidCaptcha

client = VoidCaptcha("void_a1b2c3d4e5f60718293a4b5c6d7e8f90")

result = client.solve({
    "type": "ImageToTextTask",
    "body": "iVBORw0KGgoAAAANSUhEUgAA…",
})

print(result["text"])

Example response#

A successful solve returns errorId: 0 and a solution object. The result is in solution.text. This type never opens a browser, so there is no userAgent.

solution carries those and nothing else — the gateway copies the result field, anything extra this type returns across, and drops the rest of whatever the solver sent. Timing arrives at the top level as elapsedMs, present only when the duration is known, beside cost and your remaining balance. The figures below are illustrative: nothing here is a published median.

This type also returns solution.confidence. How sure the model is, from 0 to 1. Use score in the request to have low-confidence readings refused instead of returned.

{
  "errorId": 0,
  "status": "ready",
  "solution": {
    "text": "FXBxDojZvu",
    "confidence": 0.93
  },
  "cost": "$0.0010",
  "balance": "$411.24",
  "elapsedMs": 4820
}

Errors for this type#

The codes Image to Text can return, on top of the shared authentication and billing set. Branch on errorCode, not on the HTTP status.

Every code, with the fix for each, is on the error reference. A failed solve is never charged.

Sample code#

A complete file: key from the environment, task built, errors handled, result used. Python and Node.js use the official SDK (pip install voidcaptcha, npm install voidcaptcha); the other languages call the endpoint directly.

# pip install voidcaptcha
import sys

import voidcaptcha

# The key comes from the VOIDCAPTCHA_KEY environment variable. A key in a
# committed script is a key someone else is already spending.
client = voidcaptcha.VoidCaptcha()

try:
    result = client.solve({
        "type": "ImageToTextTask",
        "body": "iVBORw0KGgoAAAANSUhEUgAA…",
    })
except voidcaptcha.SolveError as e:
    # The solve failed. It was not charged, and it is safe to retry.
    sys.exit(f"{e.code}: {e.description}")
except voidcaptcha.VoidCaptchaError as e:
    # Key, balance, limits or a bad request; e.retryable says if a retry helps.
    sys.exit(f"{e.code}: {e.description}")

print(result["text"])
print(result.cost)