herokuHeroku Error Codes


Introduction

Whenever your app experiences an error, Heroku will return a standard error page with the HTTP status code 503. To help you debug the underlying error, however, the platform will also add custom error information to your logs. Each type of error gets its own error code, with all HTTP errors starting with the letter H and all runtime errors starting with R. Logging errors start with L.

Syntax

  • H10 - App crashed
  • H11 - Backlog too deep
  • H12 - Request timeout
  • H13 - Connection closed without response
  • H14 - No web dynos running
  • H15 - Idle connection
  • H16 - Redirect to herokuapp.com
  • H17 - Poorly formatted HTTP response
  • H18 - Server Request Interrupted
  • H19 - Backend connection timeout
  • H20 - App boot timeout
  • H21 - Backend connection refused
  • H22 - Connection limit reached
  • H23 - Endpoint misconfigured
  • H24 - Forced close
  • H25 - HTTP Restriction
  • H26 - Request Error
  • H27 - Client Request Interrupted
  • H28 - Client Connection Idle
  • H80 - Maintenance mode
  • H81 - Blank app
  • H82 - Free dyno quota exhausted
  • H99 - Platform error
  • R10 - Boot timeout
  • R12 - Exit timeout
  • R13 - Attach error
  • R14 - Memory quota exceeded
  • R15 - Memory quota vastly exceeded
  • R16 – Detached
  • R17 - Checksum error
  • R99 - Platform error
  • L10 - Drain buffer overflow
  • L11 - Tail buffer overflow
  • L12 - Local buffer overflow
  • L13 - Local delivery error
  • L14 - Certificate validation error