Errors

Error codes and how to handle them

HTTP status codes

StatusMeaning
200Success
400Bad request — missing or invalid fields
401Invalid or missing API key
402Insufficient balance
429Rate limit exceeded
500Solve failed — not charged

Error response format

{
  "error": "insufficient_balance",
  "message": "Your balance is too low to complete this request."
}

Common errors

invalid_api_key

The X-API-Key header is missing or the key doesn't exist.

insufficient_balance

Your balance is below the cost of the requested solve. Top up at solver.lol.

invalid_captcha_type

The type field doesn't match any supported captcha type. Check the captcha types page for valid values.

solve_failed

The solver couldn't produce a valid token. You are not charged for failed solves. Retry the request.

missing_field

A required field (site_key, site_url, or type) is absent from the request body.