How Retry-After works
The value is either a number of seconds or an HTTP date. Well-behaved clients and SDKs honour it before retrying a rate-limited (429) or overloaded (503) request; search engine crawlers also slow down when they see it during maintenance.
Examples
HTTP/1.1 429 Too Many Requests
Retry-After: 30HTTP/1.1 503 Service Unavailable
Retry-After: Fri, 23 Oct 2026 22:00:00 GMTCheck it
curl -sI https://example.com | grep -i '^retry-after:'Paste a full set of response headers into the HTTP header checker to get every header explained and common mistakes flagged.
Related headers
- Location: gives the URL to redirect to (with 3xx) or of a newly created resource (with 201).
- Cache-Control: tells browsers, CDNs and proxies whether a response may be stored, by whom, and for how long.
- Server-Timing: reports how long the server spent on each step, shown in the browser’s network panel.
More requests, redirects and more headers
User-Agent , Host , Link , Sec-Fetch-Site , Clear-Site-Data .
Sources
Spotted a mistake? Email hello@devtoolsmith.com and we’ll fix it.
Frequently asked questions
What does the Retry-After header do?
The Retry-After response header tells the client how long to wait before trying again, after 429, 503 or a redirect. The value is either a number of seconds or an HTTP date. Well-behaved clients and SDKs honour it before retrying a rate-limited (429) or overloaded (503) request; search engine crawlers also slow down when they see it during maintenance.
How do I see the Retry-After header?
Run "curl -sI https://example.com" to print a response’s headers, or open the Network tab in your browser’s dev tools and select the request. Paste the headers into the HTTP header checker on this site to get each one explained.