API Design
Rate Limit Header Generator
Enter your rate limit parameters to generate correctly formatted RateLimit and X-RateLimit response headers with Retry-After for 429 responses.
Calculations run locally in your browserTool
About this tool
Rate Limit Header Generator
The Rate Limit Header Generator produces correctly formatted RateLimit, X-RateLimit, and Retry-After headers from rate limit parameters, covering both IETF draft and de facto standard formats.
• Generate the correct rate limit header format before implementing API rate limiting
• Check whether your rate limit headers follow the IETF draft standard or X-RateLimit convention
• Produce a 429 Retry-After header with the correct format for your reset window
• Reference rate limit header semantics when debugging a client that's ignoring limits
Next step
Continue with Utility Matrix tools for the next decision in this workflow.
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FAQ
What does this tool tell you?
The Rate Limit Header Generator produces correctly formatted RateLimit, X-RateLimit, and Retry-After headers from rate limit parameters, covering both IETF draft and de facto standard formats.
What affects the result most?
RateLimit headers (IETF draft-ietf-httpapi-ratelimit-headers): RateLimit-Limit, RateLimit-Remaining, RateLimit-Reset. X-RateLimit-* (de facto standard): X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Reset (Unix timestamp). Retry-After: seconds to wait or HTTP date — used with 429 Too Many Requests and 503.
How should I use the result?
The calculation is deterministic — the same inputs always produce the same output — so the most useful workflow is to vary one input at a time and see which factor moves the result most. That tells you where to focus your attention before committing to a decision.
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