Mockttp

Overview

Mockttp is ranked #5 of 27 in API mocking tools on Specifiction. It runs on Linux, macOS, Self-hosted, Web, Windows. There is a free plan.

Compared on API mocking tools

Dynamic responses

Yesgithub.com

Local deployment

Yesgithub.com

Supported protocols

HTTP, HTTPS, WebSocket, JSON-RPCgithub.com

Facts

What Mockttp does

Mockttp intercepts, transforms, or tests HTTP requests and responses in JavaScript.github.com · 4 Oct 2026

Testing use

Mockttp supports HTTP integration tests that can run in Node.js and browsers, including transparent proxying and HTTPS.github.com · 4 Oct 2026

Proxy use

Mockttp can be used to build custom HTTP proxies that capture, inspect, or rewrite traffic.github.com · 4 Oct 2026

Mocking features

The library can stub responses, verify requests, mock HTTPS with generated self-signed certificates, and mock traffic inside or outside its process.github.com · 4 Oct 2026

Parallel testing

Mockttp supports parallel mocking with automatically configured ports, mock URLs, and proxy settings.github.com · 4 Oct 2026

Integrations

The README example uses Mocha, Chai, and Superagent, while noting that these tools are optional and Mockttp can work with other promise-capable testing tools and HTTP clients.github.com · 4 Oct 2026

Browser setup

Browser tests require an admin server started outside the browser because browsers cannot start an HTTP server or proxy themselves.github.com · 4 Oct 2026

HTTPS certificate caution

The setup guide warns against trusting a test CA system-wide or sharing its private key, because doing so could let an attacker impersonate secure connections.github.com · 4 Oct 2026

Security support

The latest published Mockttp version is actively supported, and the preceding major version receives security fixes for six months after the next major release.github.com · 4 Oct 2026

Vulnerability reporting

Mockttp vulnerabilities can be reported through GitHub’s private security reporting channels, and confirmed vulnerabilities are to be fixed and published as advisories within 90 days.github.com · 4 Oct 2026

HTTP Toolkit privacy

HTTP Toolkit says HTTP request and response contents are never collected and are stored only locally on the user’s machine.httptoolkit.com · 4 Oct 2026

Commercial product distinction

HTTP Toolkit lists automated HTTP mocking and rewriting among Professional plan features, while Mockttp itself is published as a JavaScript library in a public GitHub repository.httptoolkit.com · 4 Oct 2026

Desktop platforms

HTTP Toolkit provides installation packages for Windows, Mac, and Linux.httptoolkit.com · 4 Oct 2026

Maker and location

The HTTP Toolkit privacy policy identifies Toolshed Labs SLU as the operator and gives its address in Barcelona, Spain.httptoolkit.com · 4 Oct 2026

Where it ranks on Specifiction

• Best API Mocking Tools in 2026#5 of 27

Sources

• github.com/httptoolkit/mockttp· checked 4 Oct 2026
• github.com/httptoolkit/mockttp/blob/main/docs/setu· checked 4 Oct 2026
• github.com/httptoolkit/mockttp/blob/main/SECURITY.· checked 4 Oct 2026
• httptoolkit.com/privacy-policy/· checked 4 Oct 2026
• httptoolkit.com/pricing/· checked 4 Oct 2026
• httptoolkit.com/docs/getting-started/installing/· checked 4 Oct 2026