Google treats HTTP 429 as an overload/rate-limit signal that can reduce crawling.

Cited by documentation

Sources

• Reduce the Google crawl rate

  Google (Search Central / Crawling infrastructure docs) · primary source · retrieved 2026-08-20

  “reduces your site's crawling rate when it encounters a significant number of URLs with 500, 503, or 429 HTTP response status codes” — 'Urgently reduce crawler traffic (for emergencies)' section

• How HTTP status codes affect Google's crawlers

  Google (Search Central / Crawling infrastructure docs) · primary source · retrieved 2026-08-20

  “treat the 429 status code as a signal that the server is overloaded” — 4xx table row for 429

  “temporarily slow down with crawling” — 5xx table intro

• Don't misuse 4xx for rate limiting Googlebot (Search Central Blog)

  Google Search Central Blog · primary source · retrieved 2026-08-20

  “needs to slow down because it's overloading the server” — 'Back to basics' section

• 429 Errors: 'Too Many Requests' and Rate Limiting Issues

  Prerender.io · retrieved 2026-08-20

  “Googlebot automatically lowers its crawl rate” — SEO consequences section

• Googlebot Crawl Slump? Mueller Points To Server Errors

  Search Engine Journal · retrieved 2026-08-20

  “I’d only expect the crawl rate to react that quickly if they were returning 429 / 500 / 503 / timeouts” — What Mueller said, lines 160-165