Migrating from 2Captcha

Switch an existing 2Captcha integration to CaptchaKings in minutes — and where native endpoints are a better fit.

Drop-In Compatibility (xCaptcha)

CaptchaKings implements the classic in.php / res.php interface, so existing 2Captcha client code works with a base-URL change:

	2Captcha	CaptchaKings
Submit	`https://2captcha.com/in.php`	`https://captchakings.com/in.php`
Retrieve / balance	`https://2captcha.com/res.php`	`https://captchakings.com/res.php`
Success response	`OK\|answer` / `{"status":1,...}`	Same (`json=1` supported)
Error strings	`KEY_DOES_NOT_EXIST`, `ERROR_ZERO_BALANCE`, ...	`KEY_DOES_NOT_EXIST`, `ZERO_BALANCE`, `NO_SUCH_CAPCHA_ID`, ...

Scope note: the compatible pair currently routes all submissions to the xCaptcha pipeline. For text OCR, Tencent, GeeTest, MTCaptcha, or Amazon WAF, migrate to the native synchronous endpoints below instead of forcing them through in.php.

Migration Steps

1. Get your API key

Register at captchakings.com and copy the API key from your dashboard. Every account starts with a $0.50 free balance — enough to test the full migration.

2. Swap the base URL

python

# Before (2Captcha)
solver = TwoCaptcha(api_key)
solver = TwoCaptcha(api_key, server='2captcha.com')

# After (CaptchaKings)
solver = TwoCaptcha('YOUR_CAPTCHAKINGS_KEY', server='captchakings.com')

Any 2Captcha-compatible library works the same way — point it at captchakings.com and keep using in.php/res.php paths.

3. Handle the faster result timing

2Captcha queues tasks for human or hybrid solvers, so clients usually poll res.php for 10–60 seconds. CaptchaKings solves xCaptcha synchronously during in.php, so the answer is ready when the task ID is returned. Your first action=get poll will normally succeed immediately — keep a short 2–5s retry loop as a safety net.

Prefer Native Endpoints for New Integrations

For anything beyond xCaptcha, call the native endpoint directly — one request, one JSON response, no polling:

Captcha Type	Native Endpoint	Guide
Text / image OCR	`POST /api/process.php`	Endpoints
Tencent & Chinese image	`POST /api/tencent.php`	Tencent docs
GeeTest v3/v4	`POST /api/geetest.php`	GeeTest docs
xCaptcha	`POST /api/xcaptcha.php`	xCaptcha docs
MTCaptcha	`POST /api/mtcaptcha.php`	MTCaptcha docs
Amazon AWS WAF	`POST /api/amazon.php`	Amazon guide

Key Differences vs 2Captcha

Speed: measured medians from 0.17s (Tencent) to 8s (Amazon WAF) — full methodology at /benchmarks.
Pricing: flat $1.00 per 1,000 solves ($0.80 per 1,000 for image OCR). No per-type surcharges.
Coverage: reCAPTCHA, hCaptcha, and Cloudflare Turnstile are not available via API today — they are on the roadmap and tracked on Supported CAPTCHAs.
No queues: native endpoints return the answer in the same response; the legacy pair is instant-poll.

Cutover Checklist

Register and fund your CaptchaKings account (free $0.50 balance covers testing).
Point the client at captchakings.com and run your existing test suite.
Verify balance reporting via res.php?action=getbalance.
Move non-xCaptcha traffic to native endpoints.
Monitor solve rates for a week against your 2Captcha baseline.

Need help? [email protected] · Troubleshooting