Retry-After Parser
A Retry-After value is either a number of seconds or an HTTP-date. Give a reference time and the page tells you when the wait ends.
The value stays in the browser. The value and the reference time are short, so they are stored in the URL and nothing is uploaded.
The reference time needs a timezone. Z means UTC. A date in the past waits 0 seconds.
Not parsed
Wait
About this tool
RFC 9110 says Retry-After is a delay in seconds or an HTTP-date. The delay is a run of digits. 0 means you can try again immediately. A fraction, a minus sign, or a unit word is not a delay.
An HTTP-date is preferably IMF-fixdate, such as Fri, 06 Nov 2026 04:02:00 GMT. The two older forms, rfc850 and asctime, are still accepted. A two-digit year that would land more than 50 years ahead is rolled back a century. If the weekday name does not match the calendar date, the calendar date is kept and the page says so.
The wait for a date is rounded up to the next whole second, so you do not retry early. A date that is already past the reference time waits 0 seconds. For a schedule you invent yourself, the exponential backoff calculatoris the other tool. This page only reads the header the server sent.
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