Solving Cloudflare Turnstile with Node.js and CaptchaAI

Cloudflare Turnstile is replacing reCAPTCHA on many sites. This guide covers the complete Node.js flow: detect Turnstile, extract the sitekey, solve via CaptchaAI, and submit the token.

Prerequisites

Node.js 18+ (native fetch)
CaptchaAI API key

Step 1: Detect and extract the sitekey

async function extractTurnstileSitekey(url) {
  const resp = await fetch(url, {
    headers: {
      "User-Agent":
        "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 Chrome/120.0.0.0 Safari/537.36",
    },
  });
  const html = await resp.text();

  // Method 1: data-sitekey attribute on Turnstile div
  const divMatch = html.match(
    /class=["'][^"]*cf-turnstile[^"]*["'][^>]*data-sitekey=["']([0-9x][A-Za-z0-9_-]+)["']/
  );
  if (divMatch) return divMatch[1];

  // Method 2: data-sitekey on any element (Turnstile keys start with 0x)
  const attrMatch = html.match(
    /data-sitekey=["'](0x[A-Za-z0-9_-]+)["']/
  );
  if (attrMatch) return attrMatch[1];

  // Method 3: In JavaScript turnstile.render call
  const jsMatch = html.match(
    /turnstile\.render\s*\([^,]+,\s*\{[^}]*sitekey\s*:\s*["']([0-9x][A-Za-z0-9_-]+)["']/
  );
  if (jsMatch) return jsMatch[1];

  // Method 4: Generic sitekey in inline script
  const inlineMatch = html.match(
    /sitekey\s*:\s*["'](0x[A-Za-z0-9_-]+)["']/
  );
  if (inlineMatch) return inlineMatch[1];

  return null;
}

Step 2: Solve Turnstile via CaptchaAI

const API_KEY = "YOUR_API_KEY";

function sleep(ms) {
  return new Promise((resolve) => setTimeout(resolve, ms));
}

async function solveTurnstile(sitekey, pageurl, action = null) {
  // Submit task
  const submitData = {
    key: API_KEY,
    method: "turnstile",
    sitekey: sitekey,
    pageurl: pageurl,
    json: "1",
  };

  if (action) {
    submitData.action = action;
  }

  const submitResp = await fetch("https://ocr.captchaai.com/in.php", {
    method: "POST",
    body: new URLSearchParams(submitData),
  });
  const submitResult = await submitResp.json();

  if (submitResult.status !== 1) {
    throw new Error(`Submit error: ${submitResult.request}`);
  }

  const taskId = submitResult.request;
  console.log(`Task ID: ${taskId}`);

  // Poll for result
  for (let i = 0; i < 30; i++) {
    await sleep(5000);

    const pollResp = await fetch(
      `https://ocr.captchaai.com/res.php?${new URLSearchParams({
        key: API_KEY,
        action: "get",
        id: taskId,
        json: "1",
      })}`
    );
    const pollResult = await pollResp.json();

    if (pollResult.status === 1) {
      return pollResult.request;
    }

    if (pollResult.request === "ERROR_CAPTCHA_UNSOLVABLE") {
      throw new Error("Turnstile unsolvable");
    }
  }

  throw new Error("Solve timed out");
}

Step 3: Submit the token

async function submitTurnstileForm(url, formData, token) {
  const body = new URLSearchParams({
    ...formData,
    "cf-turnstile-response": token,
  });

  const resp = await fetch(url, {
    method: "POST",
    headers: {
      "Content-Type": "application/x-www-form-urlencoded",
      "User-Agent":
        "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 Chrome/120.0.0.0 Safari/537.36",
    },
    body,
  });

  return {
    status: resp.status,
    body: await resp.text(),
  };
}

async function loginWithTurnstile(loginUrl, credentials) {
  // Step 1: Extract sitekey
  const sitekey = await extractTurnstileSitekey(loginUrl);
  if (!sitekey) {
    throw new Error("Turnstile sitekey not found");
  }
  console.log(`Sitekey: ${sitekey}`);

  // Step 2: Solve Turnstile
  const token = await solveTurnstile(sitekey, loginUrl);
  console.log(`Token: ${token.substring(0, 50)}...`);

  // Step 3: Submit form
  const result = await submitTurnstileForm(loginUrl, credentials, token);
  console.log(`Result: ${result.status}`);

  return result;
}

// Usage
const result = await loginWithTurnstile("https://example.com/login", {
  email: "user@example.com",
  password: "pass123",
});

Production solver class

class TurnstileSolver {
  #apiKey;

  constructor(apiKey) {
    this.#apiKey = apiKey;
  }

  async solve(sitekey, pageurl, options = {}) {
    const taskId = await this.#submit(sitekey, pageurl, options);
    return await this.#poll(taskId);
  }

  async detectAndSolve(url) {
    const sitekey = await this.#detect(url);
    if (!sitekey) throw new Error("No Turnstile found");
    return await this.solve(sitekey, url);
  }

  async #detect(url) {
    const resp = await fetch(url, {
      headers: { "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) Chrome/120.0.0.0" },
    });
    const html = await resp.text();
    const match = html.match(/data-sitekey=["'](0x[A-Za-z0-9_-]+)["']/);
    return match ? match[1] : null;
  }

  async #submit(sitekey, pageurl, options) {
    const body = new URLSearchParams({
      key: this.#apiKey,
      method: "turnstile",
      sitekey,
      pageurl,
      json: "1",
      ...(options.action && { action: options.action }),
      ...(options.cdata && { data: options.cdata }),
    });

    const resp = await fetch("https://ocr.captchaai.com/in.php", {
      method: "POST",
      body,
    });
    const data = await resp.json();

    if (data.status !== 1) throw new Error(`Submit: ${data.request}`);
    return data.request;
  }

  async #poll(taskId) {
    const params = new URLSearchParams({
      key: this.#apiKey,
      action: "get",
      id: taskId,
      json: "1",
    });

    for (let i = 0; i < 30; i++) {
      await new Promise((r) => setTimeout(r, 5000));
      const resp = await fetch(`https://ocr.captchaai.com/res.php?${params}`);
      const data = await resp.json();

      if (data.status === 1) return data.request;
      if (data.request === "ERROR_CAPTCHA_UNSOLVABLE") {
        throw new Error("Unsolvable");
      }
    }
    throw new Error("Timed out");
  }
}

// Usage
const solver = new TurnstileSolver("YOUR_API_KEY");
const token = await solver.detectAndSolve("https://example.com/login");

Turnstile with action and cData parameters

Some Turnstile implementations include action and cData parameters:

// Extract action from the page
function extractTurnstileAction(html) {
  const match = html.match(
    /data-action=["']([^"']+)["']|action\s*:\s*["']([^"']+)["']/
  );
  return match ? match[1] || match[2] : null;
}

// Solve with action
const token = await solver.solve(sitekey, pageurl, {
  action: "login",
  cdata: "session_abc123",
});

Server-side token verification

If you're building a server that verifies Turnstile tokens:

async function verifyTurnstileToken(token, ip) {
  const resp = await fetch(
    "https://challenges.cloudflare.com/turnstile/v0/siteverify",
    {
      method: "POST",
      headers: { "Content-Type": "application/x-www-form-urlencoded" },
      body: new URLSearchParams({
        secret: "YOUR_TURNSTILE_SECRET_KEY",
        response: token,
        remoteip: ip,
      }),
    }
  );

  const data = await resp.json();
  return data.success;
}

Troubleshooting

Symptom	Cause	Fix
Sitekey starts with `6Le`	That's reCAPTCHA, not Turnstile	Use `method=userrecaptcha`
Token rejected	Wrong sitekey or expired	Re-extract sitekey, submit faster
No sitekey found	Turnstile loaded via JavaScript	Use Puppeteer/Playwright instead
`ERROR_BAD_PARAMETERS`	Missing sitekey or pageurl	Check both are present
403 response after submit	Bot detection on headers	Use realistic User-Agent

Frequently asked questions

How is Turnstile different from reCAPTCHA?

Turnstile is Cloudflare's CAPTCHA replacement. It's typically invisible, faster to solve, and uses the method=turnstile API parameter instead of method=userrecaptcha.

Do I need to specify the action parameter?

Only if the site's Turnstile implementation uses it. Check for data-action in the HTML or action: in JavaScript.

What's the success rate for Turnstile solving?

CaptchaAI achieves 100% success rate on Turnstile challenges.

Summary

Solve Cloudflare Turnstile with Node.js and CaptchaAI: extract the sitekey (starts with 0x), solve via the method=turnstile API, and submit the token as cf-turnstile-response.