# Error Codes

This page documents common error codes returned by the CapMonster Cloud API along with their meanings and possible solutions.

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# Authentication & Authorization

# ERROR_KEY_DOES_NOT_EXIST

Invalid API Key The authorization key provided is not recognized or is in the wrong format.

Check your API key from the CapMonster Dashboard.

# ERROR_ZERO_BALANCE

No Funds Your account balance is zero.

Add credits to continue solving captchas.

# ERROR_IP_NOT_ALLOWED

IP Not Allowed Requests from your current IP address are not allowed.

Add your IP to the trusted list in your account settings.

# ERROR_IP_BANNED

IP Banned Too many failed requests with incorrect API key from your IP.

Verify your key, wait a few minutes, and try again.

# ERROR_IP_BLOCKED

Your IP is Blocked Your IP is permanently blocked due to repeated violations or suspicious activity.

Contact CapMonster support.

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# CAPTCHA File Issues

# ERROR_TOO_BIG_CAPTCHA_FILESIZE

Captcha Image Too Large The image size exceeds 500 KB.

Compress or resize the image before submitting.

# ERROR_ZERO_CAPTCHA_FILESIZE

Captcha Image Too Small The image size is less than 100 bytes.

Ensure the image is valid and properly encoded.

# ERROR_CAPTCHA_UNSOLVABLE

Captcha Unsolvable The image may be too noisy, corrupted, or unsupported by the service.

Try another image or adjust your task.

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# Timing & Task States

# ERROR_NO_SUCH_CAPCHA_ID / WRONG_CAPTCHA_ID

Captcha ID Not Found No task found for the given ID, or the request was made after it expired.

Poll results within 5 minutes of task creation.

# CAPTCHA_NOT_READY

Captcha Not Ready The task is still being processed.

Retry after 1-2 seconds.

# ERROR_RECAPTCHA_TIMEOUT

ReCAPTCHA Timeout Task solving took too long, possibly due to slow proxy or server issues.

Use a faster proxy or adjust timeout settings.

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# Domain & SiteKey Errors

# ERROR_DOMAIN_NOT_ALLOWED

Domain Blocked CapMonster Cloud does not support solving captchas for the specified domain.

Use a different domain or provider.

# ERROR_RECAPTCHA_INVALID_SITEKEY

Invalid SiteKey The specified websiteKey is not valid.

Double-check the data-sitekey on the target page.

# ERROR_RECAPTCHA_INVALID_DOMAIN

Invalid Domain The domain doesn't match the sitekey's origin.

Ensure both belong to the same origin.

# ERROR_TOKEN_EXPIRED

Token Expired The challenge token has expired.

Create a new task with a fresh token.

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# Task Definition Errors

# ERROR_NO_SUCH_METHOD

Incorrect Method The specified task type (in type) is invalid or unsupported.

# ERROR_TASK_NOT_SUPPORTED

Incorrect Task Type The task format is not recognized.

Review the type value and match it to the correct schema.

# ERROR_TASK_ABSENT

Missing Task Object No task object was provided, or the JSON is malformed.

# ERROR_WRONG_USERAGENT

Invalid User-Agent The specified User-Agent string is no longer accepted.

Update to a current, valid browser UA string.

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# Proxy Errors

# ERROR_PROXY_CONNECT_REFUSED

Proxy Connection Failed Unable to reach proxy server.

Test your proxy or replace it.

# ERROR_PROXY_BANNED

Proxy Banned The proxy IP is blocked by the target captcha provider.

Rotate your proxy or try a different provider.

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# Service Load & Rate Limits

# ERROR_TOO_MUCH_REQUESTS

Too Many Result Polls You polled for the task result too frequently.

Wait at least 2 seconds between requests.

# ERROR_NO_SLOT_AVAILABLE

No Free Servers All recognition servers are currently busy.

Retry after a short delay.