Errors

Every error type, what causes it, and how to fix it.

Errors use standard HTTP status codes and a consistent JSON body:

{
  "error": {
    "type": "quota_exceeded",
    "code": "plan_limit_reached",
    "message": "You've used your 25 included pages this period. Upgrade to continue.",
    "docs_url": "https://createafillablepdf.com/docs/errors"
  }
}

Status	type	Cause	Fix
400	`invalid_request`	Malformed request or missing field.	Check the request shape.
401	`authentication_error`	Missing/invalid/revoked key.	Send a valid `Authorization: Bearer` key.
402	`quota_exceeded`	Free plan out of included pages.	Upgrade or wait for the next period.
404	`not_found`	Conversion not found or not yours.	Check the ID.
415	`unsupported_file`	Not a PDF, too large, or over your per-file page limit.	Send a valid PDF within limits.
429	`rate_limit_error`	Over your per-minute rate limit.	Back off; see `Retry-After` and `X-RateLimit-*` headers.
502	`engine_error`	The document couldn't be processed.	Try another file; contact support if it persists.
500	`server_error`	Unexpected error on our side.	Retry; contact support if it persists.

We never return raw stack traces or internal details. If something looks wrong, email support@createafillablepdf.com with the conversion_id if you have one.