Mockoon – mock REST APIs in seconds

In plain words

Mockoon is a tool for creating and running mock REST API servers locally without requiring deployment or accounts. It offers an intuitive interface for designing mock APIs that work within seconds, compatible with OpenAPI specifications. The software is free and open-source, available across platforms, and includes features like HTTP request recording and proxying for complex testing scenarios. It serves developers and teams who need to test applications against APIs during development.

written from the facts on this page · September 2026

From the sources

Mockoon is the easiest and quickest way to design and run mock REST APIs. No remote deployment, no account required, free and open-source . Proudly built and operated in Europe, with privacy and transparency at the core. Get working mock REST APIs in seconds with an intuitive and easy-to-use interface. Run them everywhere with the CLI. Compatible with the OpenAPI specification, Mockoon integrates perfectly with your existing applications and API design workflow. Go beyond mocking with advanced features and tackle the most complex situation with HTTP requests recording, proxying, integration testing, etc. Mockoon offers a wide range of features to create the most realistic mock APIs: dynamic…from mockoon.com

• 
  Mockoon2017 · mockoon.com · ▲89

  Mock servers in seconds

• 
  HTTP Mock – Intercept, debug and mock HTTP(S) with zero setup2019 · httptoolkit.tech · ▲341

  Beautiful, cross-platform & open-source tools for debugging, testing and building with HTTP(S), on Windows, Linux & Mac.

• MO
  Mockit – Open-source app to create and configure HTTP mocked endpoints2019 · mockit.netlify.com · ▲158
• 
  Mocktail – Free, open-source mock API server with a built-in dashboardAug 2026 · getmocktail.com · ▲25

  Hi HN, I built the first version of Mocktail years ago. I recently came back to the project, and after a pretty substantial rebuild, v4 is now out. Mocktail is a free and open-source, self-hosted mock API server with a built-in dashboard and database, packaged as a single ~25 MB binary. You can run it locally or on your own infrastructure — no account or hosted service required. You can define endpoints and responses, generate realistic data per request, customize headers, status codes and latency, and inspect incoming requests in real time. With v4, I also added MCP support, so coding…

• MS
  Mocktastic – Simple, Offline mock REST APIs for your entire team2018 · mocktastic.com · ▲43
• 
  Mocklets2018 · mocklets.com · ▲82

  A HTTP-based API simulator to assist parallel development 🛠️

• 
  /dev/null▲482

  a social network for devs

  Dev tools · 3d ago · dev-null.sh

• 
  Whiteboard (YC W26) – an open-source IDE for thoughtful software design▲423

  open-source IDE for thoughtful software design. Contribute to devdotfast/whiteboard development by creating an account on GitHub.

  Dev tools · 27d ago · github.com

• 
  Reladraw – A diagram language where you decide where to place things▲411

  Contribute to reladraw/reladraw development by creating an account on GitHub.

  Dev tools · 25d ago · github.com

• 
  OpenBot▲362

  Grok Bot alternative: free, local, open-source, multiplayer

  Dev tools · 23d ago · openbot.run

• 
  Talanoa▲346

  Hi HN, I’m a fullstack developer, and honestly, I’ve lost count of how many side projects I’ve worked on over the years. But one idea kept coming back to me: a different kind of email client. It first came to me in 2014: “What if we could handle emails more like conversations?” Every year, I’d revisit this concept in my “Build Notes.” Ten years later, no one had built exactly what I had in mind — so I finally decided to do it myself. That’s how Talanoa was born. I wanted something focused on people, not timelines. I was tired of marking messages as unread just to remember to reply later, or…

  Dev tools · 20d ago · talanoa.email

• 
  CoreSpeed▲332

  One MCP for everything your agents need: apps, memory, tools

  Dev tools · 28d ago · corespeed.io

• 
  Coda▲1,647

  It's a new day for docs

  Work · 2017 · coda.io

• 
  Station▲1,377

  One app to rule them all

  Work · 2017 · stationhq.com

• 
  New Google Calendar▲1,041

  Google is launching a new look + new features for Calendar

  Work · 2017 · support.google.com

• 
  InVision Studio▲999

  The world’s most powerful screen design tool

  Work · 2017 · miro.com

• 
  Slite▲876

  One combined workspace. All of your team documentation.

  Work · 2017 · slite.com

• 
  Stripe Elements▲817

  Beautiful, smart checkout flows 💳💸

  Commerce · 2017 · stripe.com