Why is my Messaging API Request Receiving an HTTP Error 413?


  • Why is my messaging API request receiving an HTTP error 413?
  • Why am I getting 413 Request Entity Too Large errors?
  • What is the maximum API request size?
  • Is there a messaging API request size limit or cap?


If you are experiencing SMS send failures with status code "413 Request Entity Too Large", this is due to an oversized API request.

We cap the maximum request size at 4000 characters for all of the APIs (and at 8000 for TTS), to protect our platform from potential attacks overwhelming our backend. 

Please feel free to contact us via email to or our support portal at if you have any further questions.

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