Toronto SEO
All HTTP status codes
4xx Client Error
RFC 9110

415 Unsupported Media Type

The request's Content-Type is not supported by the server for this resource.

What it means

HTTP 415 Unsupported Media Type indicates the server refuses to accept the request because the payload format is not supported. The Accept-Patch or Accept response header may indicate supported formats.

When it's used

API endpoints requiring application/json receiving form-encoded data, or vice versa.

Common causes
  • Sent application/x-www-form-urlencoded to a JSON-only API
  • Wrong Content-Type header set by client
  • Multipart upload to a JSON endpoint
  • Missing Content-Type entirely
How to fix it
  • Set the correct Content-Type header (e.g., application/json)
  • Verify the API documentation for accepted media types
  • Check the Accept-Patch header in the response for supported formats
Example response
HTTP/1.1 415 Unsupported Media Type
Accept: application/json
SEO impact

API-only. Not relevant to HTML page indexing.