CAPTCHA Solve Rate Drops: Performance Regression Diagnosis

Your CAPTCHA solve rate dropped from 95% to 60% overnight. Before contacting support, this guide walks through a structured diagnosis to pinpoint the root cause — whether it's your code, proxy, target site, or CaptchaAI service.

Diagnostic Decision Tree

Solve rate dropped
├── Is the API returning errors? → Check error codes
│   ├── ERROR_WRONG_USER_KEY → API key issue
│   ├── ERROR_ZERO_BALANCE → Balance depleted
│   ├── ERROR_NO_SLOT_AVAILABLE → Rate limiting
│   └── ERROR_CAPTCHA_UNSOLVABLE → CAPTCHA changed
├── Are tokens returned but rejected by the target site?
│   ├── Token expired before submission → Speed up injection
│   ├── Sitekey changed → Re-extract from page
│   └── Domain mismatch → Check pageurl parameter
├── Are proxies failing?
│   ├── Proxy banned by target → Rotate proxies
│   └── Proxy timeout → Check proxy health
└── Did the target site change?
    ├── New CAPTCHA type → Update method parameter
    ├── JavaScript changes → Re-analyze page
    └── Rate limiting by site → Reduce frequency

Step 1: Check CaptchaAI Error Codes

Run a quick diagnostic script:

# diagnose_solve_rate.py
import os
import requests
from collections import Counter

API_KEY = os.environ.get("CAPTCHAAI_KEY", "YOUR_API_KEY")

def check_balance():
    """Verify API key and balance."""
    resp = requests.get("https://ocr.captchaai.com/res.php", params={
        "key": API_KEY, "action": "getbalance", "json": "1",
    })
    result = resp.json()
    print(f"Balance: {result}")
    return result

def test_solve(sitekey, pageurl, runs=5):
    """Run test solves and collect error statistics."""
    errors = Counter()
    successes = 0

    for i in range(runs):
        # Submit
        resp = requests.get("https://ocr.captchaai.com/in.php", params={
            "key": API_KEY,
            "method": "userrecaptcha",
            "googlekey": sitekey,
            "pageurl": pageurl,
            "json": "1",
        })
        result = resp.json()

        if result.get("status") != 1:
            errors[result.get("request", "UNKNOWN")] += 1
            print(f"  Run {i+1}: Submit error: {result.get('request')}")
            continue

        task_id = result["request"]
        import time
        time.sleep(15)

        # Poll
        for _ in range(25):
            poll = requests.get("https://ocr.captchaai.com/res.php", params={
                "key": API_KEY, "action": "get",
                "id": task_id, "json": "1",
            })
            poll_result = poll.json()

            if poll_result.get("status") == 1:
                successes += 1
                print(f"  Run {i+1}: Solved")
                break
            if poll_result.get("request") != "CAPCHA_NOT_READY":
                errors[poll_result.get("request", "UNKNOWN")] += 1
                print(f"  Run {i+1}: Error: {poll_result.get('request')}")
                break
            time.sleep(5)
        else:
            errors["TIMEOUT"] += 1
            print(f"  Run {i+1}: Timeout")

    print(f"\nResults: {successes}/{runs} solved")
    if errors:
        print(f"Errors: {dict(errors)}")

# Run diagnostics
print("=== Balance Check ===")
check_balance()

print("\n=== Test Solves ===")
test_solve("YOUR_SITEKEY", "https://your-target-site.com", runs=5)

Step 2: Verify Target Site Parameters

The most common cause of solve rate drops is a changed sitekey or page structure.

Check if the sitekey changed

Visit the target page, open DevTools (F12), and search for:

• reCAPTCHA: data-sitekey or grecaptcha.render call
• Cloudflare Turnstile: data-sitekey in the Turnstile widget
• GeeTest: gt parameter in the GeeTest initialization

Compare with the sitekey in your code. A single changed character causes 100% failure.

Check if the CAPTCHA type changed

Some sites migrate between CAPTCHA providers:

• reCAPTCHA v2 → reCAPTCHA v3 (invisible)
• reCAPTCHA → Cloudflare Turnstile
• Image CAPTCHA → reCAPTCHA Enterprise

If the type changed, update your method parameter accordingly.

Step 3: Evaluate Proxy Health

Proxy quality directly affects solve rates, especially for token-based CAPTCHAs where CaptchaAI uses your proxy.

Test without a proxy first (if the CAPTCHA type supports proxyless solving) to isolate whether the proxy is the issue.

Step 4: Check Token Timing

CAPTCHA tokens have limited validity:

If your pipeline takes too long between receiving the token and injecting it into the form, the token expires and the site rejects it.

Fix: Measure the time between getTaskResult and form submission. If > 60 seconds, optimize your pipeline.

Step 5: Analyze Error Distribution

Sort your errors by frequency to find the root cause:

Step 6: Compare Against Baseline

If you ran benchmarks previously, compare current metrics against your baseline:

When to Contact Support

Contact CaptchaAI support if:

• All diagnostic steps pass but solve rate remains low
• ERROR_CAPTCHA_UNSOLVABLE rate exceeds 20% on previously working sitekeys
• Balance shows correct but solves still fail
• The issue persists for more than 2 hours

Include in your report:

1. CAPTCHA type and sitekey
2. Target site URL
3. Error distribution (from diagnostic script)
4. When the issue started
5. Any changes you made to your code

Troubleshooting Quick Reference

FAQ

Can CaptchaAI's solve rate change for a specific site?

Yes. If a site upgrades its CAPTCHA configuration (e.g., harder challenges, enterprise features), solve rates can temporarily decrease until CaptchaAI's solvers adapt.

Should I report every ERROR_CAPTCHA_UNSOLVABLE?

No. A 2–5% unsolvable rate is normal for complex CAPTCHAs. Report only if the rate exceeds 15–20% consistently.

How quickly should I expect solve rates to recover?

If the issue is on CaptchaAI's side, recovery typically happens within hours. If the target site changed, you may need to update your integration parameters.

Related Articles

• Captcha Solve Rate Sli Slo Monitoring
• Time Series Captcha Solve Performance Trends
• Captcha Solve Success Rate Dropping Diagnosis

Next Steps

Keep your CAPTCHA pipeline healthy — get your CaptchaAI API key.

Related guides:

• CaptchaAI Error Codes Reference
• Proxy Quality Affects Solve Rate
• Benchmarking Solve Times