https://zerocaptcha.io/guides Guides to Cloudflare Turnstile, CAPTCHA-solving APIs and ZeroCaptcha: tokens, sitekeys, callbacks, errors, migrations and costs. en Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/captcha-api-error-codes https://zerocaptcha.io/guides/captcha-api-error-codes ERROR_CAPTCHA_UNSOLVABLE, ERROR_ZERO_BALANCE, ERROR_KEY_DOES_NOT_EXIST and the rest: what each captcha API error means, whether to retry, and what it costs. API Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/captcha-solver-callbacks https://zerocaptcha.io/guides/captcha-solver-callbacks Get Cloudflare Turnstile results pushed to your server instead of polling: callbackUrl and pingback, what each call contains, retries, and how to answer. API Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/rate-limits-and-concurrency https://zerocaptcha.io/guides/rate-limits-and-concurrency Run many Cloudflare Turnstile tasks at once: how ZeroCaptcha paces calls, what 429, ERROR_RATE_LIMIT and ERROR_NO_SLOT_AVAILABLE mean, and how to back off. API Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/captcha-solving-cost https://zerocaptcha.io/guides/captcha-solving-cost How captcha solving is priced per 1,000, why the real cost differs from the list price, and how to estimate a month of Cloudflare Turnstile tasks. Billing Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/cloudflare-challenge-vs-turnstile https://zerocaptcha.io/guides/cloudflare-challenge-vs-turnstile The "Just a moment..." page and the Cloudflare Turnstile widget are different features. How each works, what it produces, and how to tell which you face. Cloudflare Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/cloudflare-turnstile-action-and-cdata https://zerocaptcha.io/guides/cloudflare-turnstile-action-and-cdata What Turnstile's action and cData parameters do, where to find them in a page, and how to pass them in createTask, in.php or REST so the token is accepted. Cloudflare Turnstile Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/cloudflare-turnstile-widget-modes https://zerocaptcha.io/guides/cloudflare-turnstile-widget-modes Cloudflare Turnstile's three widget modes compared: what visitors see in each, how to tell which one a page uses, and why a solving task is the same for all. Cloudflare Turnstile Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/cloudflare-turnstile-token-expiry https://zerocaptcha.io/guides/cloudflare-turnstile-token-expiry Cloudflare Turnstile tokens last 300 seconds and work once. Why tokens expire, what timeout-or-duplicate means, and how to use each token before it runs out. Cloudflare Turnstile Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/createtask-gettaskresult-explained https://zerocaptcha.io/guides/createtask-gettaskresult-explained How the createTask, getTaskResult and getBalance format works: request bodies, replies, errorId, polling, and ZeroCaptcha's Cloudflare Turnstile tasks. API Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/find-cloudflare-turnstile-sitekey https://zerocaptcha.io/guides/find-cloudflare-turnstile-sitekey Find a Cloudflare Turnstile sitekey in data-sitekey, in turnstile.render() or in the network log, and check you have the right one before you send a task. Cloudflare Turnstile Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/idempotency-keys-for-captcha-tasks https://zerocaptcha.io/guides/idempotency-keys-for-captcha-tasks Use an Idempotency-Key header so a retried createTask never makes a second task: how keys work for 24 hours, the two key errors, and finding a lost task. API Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/migrate-from-2captcha https://zerocaptcha.io/guides/migrate-from-2captcha Move Cloudflare Turnstile solving from 2Captcha to ZeroCaptcha: keep in.php and res.php or createTask, change the host and key, and check what differs. Migration Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/migrate-from-anti-captcha https://zerocaptcha.io/guides/migrate-from-anti-captcha Move Cloudflare Turnstile tasks from Anti-Captcha to ZeroCaptcha: the same task types, calls and field names, cData included, and what to check first. Migration Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/migrate-from-capsolver https://zerocaptcha.io/guides/migrate-from-capsolver Move Cloudflare Turnstile tasks from CapSolver to ZeroCaptcha: AntiTurnstileTaskProxyLess and its metadata fields work as they are. Change host and key. Migration Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/pay-for-captcha-api-with-crypto https://zerocaptcha.io/guides/pay-for-captcha-api-with-crypto How crypto top-ups work on ZeroCaptcha: invoices in US dollars, the hosted checkout, confirmations, under- and overpayments, receipts, and final top-ups. Billing Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/responsible-captcha-automation https://zerocaptcha.io/guides/responsible-captcha-automation When using a captcha solver is appropriate, what ZeroCaptcha's Acceptable Use Policy allows, and how site owners opt out or report abuse, all handled by people. Security Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/cloudflare-turnstile-web-scraping https://zerocaptcha.io/guides/cloudflare-turnstile-web-scraping Collect data you are allowed to collect from pages behind Cloudflare Turnstile: when a solver fits, how to add it to a pipeline, and when to ask first. Cloudflare Turnstile Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/secure-captcha-api-keys https://zerocaptcha.io/guides/secure-captcha-api-keys Protect a captcha API key and your balance: scopes, IP allowlists, daily spend caps, rotation with an overlap, instant revocation, and spotting a leaked key. Security Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/solve-cloudflare-turnstile-with-a-proxy https://zerocaptcha.io/guides/solve-cloudflare-turnstile-with-a-proxy When to solve Turnstile through your own proxy, how to pass it in createTask, in.php or REST, which proxy types work, and what a bad proxy costs you. API Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/submit-cloudflare-turnstile-token https://zerocaptcha.io/guides/submit-cloudflare-turnstile-token Where a solved Turnstile token goes: the cf-turnstile-response field, the widget's callback, or a JSON body. With examples for forms, fetch and browsers. Cloudflare Turnstile Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/test-cloudflare-turnstile-in-ci https://zerocaptcha.io/guides/test-cloudflare-turnstile-in-ci Test your own Turnstile forms in CI with Cloudflare's testing sitekeys and secret keys: always pass, always fail, forced challenges, and spent tokens. Testing Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/cf-clearance-cookie-explained https://zerocaptcha.io/guides/cf-clearance-cookie-explained What Cloudflare's cf_clearance cookie is, what it is tied to, how long it lasts, and how to reuse it correctly with the same user agent through the same proxy. Cloudflare Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/verify-webhook-hmac-signature https://zerocaptcha.io/guides/verify-webhook-hmac-signature Check a ZeroCaptcha callback's HMAC-SHA256 signature in Node, Python or Go: the raw body, a constant-time compare, the timestamp window and secret rotation. Security Wed, 30 Sep 2026 00:00:00 GMT https://zerocaptcha.io/guides/what-is-cloudflare-turnstile https://zerocaptcha.io/guides/what-is-cloudflare-turnstile Cloudflare Turnstile explained: the widget, the token it issues, how a site verifies it, and what that means when you automate a page that shows it. Cloudflare Turnstile Wed, 30 Sep 2026 00:00:00 GMT