What a 429 rate-limit error means, how Retry-After works and how to stop hitting it
Runs in your browser. Nothing you type is sent anywhere. Updated on 25 Oct 2026.A 429 means you sent more requests in a period than the server allows, and it is refusing more for now. RFC 6585 defines it and says the reply may carry Retry-After, the seconds or date to wait before trying again. To stop hitting it, honour that header, back off exponentially between retries, cache answers instead of asking twice, and spread scheduled jobs out rather than firing them all at once.
Open the page with 429 Too Many Requests already selected.
Read "When to use it": rate limiting, which should always come with a Retry-After header.
In your client, wait the Retry-After time, then retry with a growing delay between attempts.
Choose a language under "Send this code in" and press Copy snippet for a 429 that sends Retry-After.
This HTTP status codes reference lists every registered code from 100 to 511, plus the unregistered ones that nginx, Apache, Laravel and Cloudflare return. Each entry says what the code actually means, when to send it, whether a cache may store the response without cache headers, whether a redirect changes the request method, and which RFC defines it.
Search works three ways. Type a number such as 404, or a class such as 4xx, to jump straight to it. Type a name such as "not found". Or describe what you want to express, and the intent search finds the code: "login failed" gives 401, "rate limit" gives 429, "file too large" gives 413, "validation failed" gives 422.
Every common code comes with a copyable snippet for raw HTTP, Express, Fastify, FastAPI, Go and PHP, including the header that code requires, such as WWW-Authenticate on a 401 or Allow on a 405. Nothing is sent anywhere; the whole table is in the page.
The rest of the article, and all 6 questions about HTTP Status Codes, are on the HTTP Status Codes page.
Use 401 Unauthorized. It means the server does not know who you are, so a missing, expired or wrong credential belongs there. Use 403 Forbidden only when you know who the caller is and are still refusing. The specification wants a WWW-Authenticate header on every 401.
401 means unauthenticated: send credentials and try again. 403 means authenticated but not allowed: better credentials will not help. If revealing that a record exists is itself a leak, some APIs answer 404 instead of 403 so an attacker learns nothing.
RFC 9110 section 15.1 lists 200, 203, 204, 206, 300, 301, 308, 404, 405, 410, 414 and 501 as heuristically cacheable, and RFC 7725 adds 451. A cache may store those with no Cache-Control or Expires header, which is why a temporary 404 can persist. Every other code needs explicit cache headers.
418 I'm a Teapot comes from RFC 2324, an April Fools' joke from 1998 about a coffee pot protocol. A 2017 proposal to reuse the number was withdrawn after objections, so it stays reserved in the IANA registry and must never be used for a real meaning.
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