httpbin.org

[ Base URL: httpbin.org/ ]

A simple HTTP Request & Response Service.

Other Utilities

HTML form that posts to /post /forms/post

Usage limits

On httpbin.org, each client IP can make about 17 requests per second, and 2 per second to the body-echo endpoints (/post, /put, /patch, /delete, /anything and the others that send your request body back).
Request bodies can be up to 1 MiB.
Over a limit, you get 429 Too Many Requests with a Retry-After header: wait that many seconds before trying again.
On httpbin.org, clients that keep exceeding the limits may be blocked for a while.
A request that is too large or malformed gets a 4xx response that says why.

Proxy headers

httpbin.org sits behind proxies, so /headers and the headers field of every response hide the headers they add (X-Forwarded-For, X-Real-Ip, Via and similar). Add the query parameter show_env (?show_env=1, any value) to see them: /headers?show_env=1. It also shows cookies that are hidden by default.