415 Unsupported Media Type
The request's Content-Type header specifies a format that the server doesn't understand or support for the requested endpoint. The server might accept the same data in a different format.
What can I do?
- Check the URL for typos — a single wrong character causes most 4xx errors.
- Try navigating to the site's homepage and searching from there.
- If the problem persists after retrying, contact the site owner.
How to debug & fix
- Always validate Content-Type early and return 415 with accepted types listed
- Include Accept header in response with the types you do accept
- Common mistake: forgot Content-Type: application/json when testing with curl
- Document your accepted Content-Type(s) prominently in your API reference — forgetting application/json is the most common client mistake.
Code Example
app.post('/api/data', (req, res, next) => {
if (req.headers['content-type'] !== 'application/json') {
return res.status(415).json({
error: 'Unsupported Media Type',
accepted: ['application/json']
});
}
next();
});Related Status Codes
How HTTP Status Codes Work
Every HTTP response carries a three-digit status code that tells the client — browser, API consumer, or search-engine crawler — exactly what happened. The first digit defines the class: 1xx informational (request in progress), 2xx success, 3xx redirection, 4xx client error (bad request, missing auth, not found), and 5xx server failure.
Status codes are standardised in RFC 9110 (HTTP Semantics, 2022). Extensions like WebDAV (RFC 4918) and rate-limit headers (RFC 6585) added codes beyond the core set. When a client receives an unrecognised code, the rule is to treat it as the generic x00 of its class.
Why the Right Code Matters
Semantically correct codes help search engines index accurately (301 passes link equity; 410 removes pages faster than 404), allow API clients to implement correct retry logic (429 + Retry-After, 503 + Retry-After), and let monitoring systems distinguish bugs (500) from load issues (503) from auth failures (401/403).
Looking up a different status code? The full reference covers all HTTP codes with causes, fix guides, and copyable code examples for Node.js and Python.
Browse the full HTTP Status Code reference →