Mockbin alternatives (mockbin.org is gone)

If a tutorial, test suite, or old Stack Overflow answer pointed you at mockbin.org and you're getting DNS errors: the site is gone. As of our last check (August 2026), neither mockbin.org nor mockbin.com resolves at all — not a redirect, not a sunset notice, just no DNS. Another entry in the free-dev-tool graveyard alongside the original requestb.in and Hookbin.

What happened to it

Mockbin was built at Mashape and later maintained by Kong. The code is still open source — the repo now lives as Kong/insomnia-mockbin — and the hosted functionality was folded into Insomnia's mock servers. So the capability survives, but the public no-signup mockbin.org endpoint that thousands of docs and test configs pointed at does not.

Mockbin did two different jobs

Pick your replacement based on which one you were using:

• Request bins — a URL that captures whatever you send it, so you can inspect method, headers, and body.
• Mocked responses — endpoints that answer with a status/headers/body you define (Mockbin did this from HAR files).

1. CatchHook (this site) — inspection + configurable responses

$ curl https://catchhook.catchhook.workers.dev/new        # instant bin, no signup

• Instant bin, one curl or one click, no account. Anonymous bins live 24 h; a free account gives 1,000 requests per bin and 30-day retention. No paid tier exists.
• Full inspection: headers, query, form fields decoded, JSON pretty-printed, binary bodies byte-exact with a hex view.
• Configurable responses per bin — status, headers, body, delay, plus templates like {{body.challenge}} that echo request fields back. This covers Mockbin's most common mock use (fixed responses, echo endpoints, and URL-verification handshakes like Slack/Zoom) without HAR files.
• Webhook extras Mockbin never had: ✓/✗ HMAC signature badges (GitHub, Stripe, Shopify, generic), one-click replay to your real endpoint, copy-as-curl/fetch/ Python/HTTPie, request diff, HAR export, a CLI with live tail and a localhost relay.

Trade-offs, honestly: one response config per bin — no path-based routing, so if you need GET /users and POST /orders to behave differently on one host, use a real mock server (below).

2. Self-host the original

Kong/insomnia-mockbin is Node + Redis and runs fine in Docker. You get exact Mockbin behavior — HAR-based mocks, the /request echo endpoint — at the cost of running it yourself and exposing it publicly if a webhook provider needs to reach it.

3. Insomnia mock servers

Kong's official successor. Cloud-hosted mocks tied to the Insomnia app and an account — good if your team already lives in Insomnia, heavier if you just wanted a throwaway URL.

4. Mock-first tools

• Beeceptor — hosted, has routing rules; free tier is ~50 requests/day. Comparison.
• Mockoon / WireMock — excellent self-hosted mock servers, free forever, but no public URL without a tunnel.

Quick chooser

• "I just need a URL to see what's being sent" → CatchHook.
• "My webhook needs a specific response back" → CatchHook response config, or Beeceptor if you need per-path rules.
• "I need Mockbin's exact HAR behavior" → self-host insomnia-mockbin.

← All guides · Docs · CatchHook vs webhook.site