About

About ratelimitlens

A free, open parser that turns pasted 429/503 headers into one answer: when can I retry?

Hit a rate limit and the headers rarely give a straight answer. Is x-ratelimit-reset a Unix timestamp in seconds, in milliseconds, or just the number of seconds until the window resets? Is Retry-After a count of seconds or an HTTP-date? Different APIs answer differently, and getting it wrong means retrying too early (and getting blocked again) or waiting far too long.

ratelimitlens turns a pasted block of HTTP response headers into a single answer: when can I retry, how much quota is left, and what does each header mean. The hard part it solves is ambiguity — *-Reset can be epoch seconds, epoch milliseconds, or a countdown, and Retry-After can be seconds or a date. It disambiguates by a disclosed magnitude heuristic (with a manual override), follows RFC 9110 for Retry-After, and supports the X-RateLimit-*, legacy RateLimit-* and new IETF combined RateLimit conventions. 100% client-side; no header ever leaves your browser.

It reads the X-RateLimit-* family, the legacy RateLimit-* headers, the new IETF combined RateLimit header, and the specific dialects of GitHub, Twitter/X, Discord and GitLab — then shows the absolute retry time, a live countdown, the quota remaining, and a per-header explanation. Because it is a static page, every header you paste stays in your browser. Parse your headers →