HTTP 429 — Too Many Requests
4xx Client Error
What it means
The client has been rate limited.
What to do about it
Back off and retry, honouring the Retry-After header. If you control the client, add exponential backoff with jitter — synchronised retries make the problem worse.
Where it sits
429 belongs to the 4xx family: The request contains something the server will not or cannot process. The fix is normally on the client side.
HTTP/1.1 429 Too Many RequestsChecking it yourself
# see the status code and headers only
curl -sI https://example.com/path
# follow redirects and print each hop
curl -sIL -o /dev/null -w "%{http_code} %{url_effective}\n" https://example.com/path
# JavaScript
const r = await fetch(url);
console.log(r.status, r.statusText);How this code behaves
| Cacheable by default | No — caches must not store this response unless explicit cache headers permit it. |
| Safe to retry | Yes, with backoff. This is a transient condition; retrying the same request is reasonable. |
| Effect on search indexing | No direct effect. |
Returning 429 correctly
# nginx
return 429;
# Express
res.status(429).json({ error: 'Too Many Requests' });
# Go
w.WriteHeader(429)
# Python (Flask)
return jsonify(error='Too Many Requests'), 429;Frequently asked questions
What does HTTP 429 mean?
The client has been rate limited.
How do I fix a 429 error?
Back off and retry, honouring the Retry-After header. If you control the client, add exponential backoff with jitter — synchronised retries make the problem worse.
Is 429 a client or server problem?
A client problem by definition — the request needs to change. That said, a 4xx can still be the server’s fault if it is misconfigured and rejecting valid requests.