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HTTP Status Code
415 Unsupported Media Type
Client ErrorThe server refused the request because the payload format is not supported.
HTTP status code reference, response example, common causes, fixes, and related status codes.
What does HTTP 415 Unsupported Media Type mean?
HTTP 415 Unsupported Media Type is a status code sent by a server to indicate the result of an HTTP request.
Status codes help browsers, APIs, apps, and backend systems understand whether a request succeeded, failed, was redirected, or needs additional action.
In practice, HTTP 415 Unsupported Media Type usually appears when a server responds under specific request, validation, permission, or infrastructure conditions.
Response example
HTTP/1.1 415 Unsupported Media Type
HTTP example
HTTP/1.1 415 Unsupported Media Type
Relevant headers
Content-Type
Content-Type: application/json
Common causes
- Wrong Content-Type header
- Sending form data to a JSON-only API
- Unsupported file type upload
How to fix it
- Use the correct Content-Type header
- Send data in a format supported by the server
Common mistakes
- Assuming the status code alone explains the full backend issue
- Ignoring related response headers that add important context
- Treating temporary errors as permanent failures
- Retrying too aggressively without checking the cause
- Debugging the frontend only when the problem is server-side
How browsers and APIs use it
Browsers, APIs, and backend services use HTTP status codes to understand the outcome of a request. Depending on the status code, an application may render content, retry a request, redirect the user, show an error, or trigger a different flow in the client or server.
Developer note
HTTP 415 is one of the most common API integration mistakes. Always confirm what content type the endpoint expects.
Client-side example
await fetch("/api/items", {
method: "POST",
headers: {
"Content-Type": "application/json",
},
body: JSON.stringify({ name: "Item" }),
});