Image to Text

Image to Text is the most common recognition task. Send a base64-encoded image of a CAPTCHA and receive the text content. This task type processes images directly on the provider side — no proxy variants are needed.

Recognition tasks typically return results synchronously with the createTask response. If the result is not immediately available, poll with getTaskResult as usual.

Task Type

Type	Description
ImageToTextTask	Recognize text from a CAPTCHA image

Parameters

Parameter	Type	Required	Description
type	string	Yes	ImageToTextTask
body	string	Yes	Base64-encoded image (PNG, JPG, GIF)
case	boolean	No	true if the answer is case-sensitive
numeric	integer	No	1 = digits only, 2 = letters only, 0 = any
minLength	integer	No	Minimum answer length
maxLength	integer	No	Maximum answer length
phrase	boolean	No	true if the answer contains a space
math	boolean	No	true if the answer is a math result
comment	string	No	Instructions for the solver

Create Task

Request

{
  "clientKey": "YOUR_API_KEY",
  "task": {
    "type": "ImageToTextTask",
    "body": "iVBORw0KGgoAAAANSUhEUg...",
    "numeric": 1,
    "minLength": 4,
    "maxLength": 6
  }
}

Response

{
  "errorId": 0,
  "status": "ready",
  "solution": {
    "text": "abc123"
  }
}

Solution Object

{
  "text": "abc123"
}

Field	Type	Description
text	string	The recognized text from the CAPTCHA image

Code Examples

Python

import requests
import base64

API_KEY = "YOUR_API_KEY"

# Encode the CAPTCHA image to base64
with open("captcha.png", "rb") as f:
    image_data = base64.b64encode(f.read()).decode()

# Create task
response = requests.post("https://api.ucaptcha.net/createTask", json={
    "clientKey": API_KEY,
    "task": {
        "type": "ImageToTextTask",
        "body": image_data,
        "numeric": 0,
        "minLength": 4,
        "maxLength": 8
    }
}).json()

if response.get("status") == "ready":
    print("Solution:", response["solution"]["text"])
else:
    # Poll if not immediately ready
    import time
    task_id = response["taskId"]
    while True:
        result = requests.post("https://api.ucaptcha.net/getTaskResult", json={
            "clientKey": API_KEY,
            "taskId": task_id
        }).json()

        if result["status"] == "ready":
            print("Solution:", result["solution"]["text"])
            break
        elif result["status"] == "failed":
            print("Error:", result.get("errorDescription"))
            break

        time.sleep(5)

JavaScript

import { readFileSync } from "fs";

const API_KEY = "YOUR_API_KEY";

// Encode the CAPTCHA image to base64
const imageData = readFileSync("captcha.png").toString("base64");

// Create task
const response = await fetch("https://api.ucaptcha.net/createTask", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify({
    clientKey: API_KEY,
    task: {
      type: "ImageToTextTask",
      body: imageData,
      numeric: 0,
      minLength: 4,
      maxLength: 8
    }
  })
}).then(r => r.json());

if (response.status === "ready") {
  console.log("Solution:", response.solution.text);
} else {
  // Poll if not immediately ready
  const taskId = response.taskId;
  while (true) {
    const result = await fetch("https://api.ucaptcha.net/getTaskResult", {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({ clientKey: API_KEY, taskId })
    }).then(r => r.json());

    if (result.status === "ready") {
      console.log("Solution:", result.solution.text);
      break;
    } else if (result.status === "failed") {
      console.error("Error:", result.errorDescription);
      break;
    }

    await new Promise(r => setTimeout(r, 5000));
  }
}

cURL

# Encode image to base64
IMAGE_BASE64=$(base64 -w 0 captcha.png)

# Create task
curl -X POST https://api.ucaptcha.net/createTask \
  -H "Content-Type: application/json" \
  -d "{
    \"clientKey\": \"YOUR_API_KEY\",
    \"task\": {
      \"type\": \"ImageToTextTask\",
      \"body\": \"$IMAGE_BASE64\",
      \"numeric\": 0,
      \"minLength\": 4,
      \"maxLength\": 8
    }
  }"

# Poll for result if not immediately ready (replace TASK_ID)
curl -X POST https://api.ucaptcha.net/getTaskResult \
  -H "Content-Type: application/json" \
  -d '{
    "clientKey": "YOUR_API_KEY",
    "taskId": "TASK_ID"
  }'

Tip

Use the comment parameter to give the solver additional context about the CAPTCHA format. For example, "comment": "Only lowercase letters, no numbers" can improve accuracy.

Note

The body parameter must contain a valid base64-encoded image. Do not include the data:image/png;base64, prefix — send only the raw base64 string.

Provider Coverage

• 2Captcha
• CapSolver
• Anti-Captcha
• CapMonster
• DeathByCaptcha
• 2Crawler
• Multibot