Sparrow - The lightest and fastest platform for API testing

Introducing Sparrow: Built for the Future of API Development

In 2025, speed, clarity, and developer autonomy aren’t optional—they’re essential. That’s why Sparrow has evolved, blending input from developers in 25+ countries with our relentless pursuit of a better, faster, smarter API experience.

Here’s what’s new (and blazing fast):

Security and Compliance:

✅ Self Hosting – Deploy Sparrow securely on-prem or in your private cloud; Also available in Azure and AWS Marketplaces

✅ Sparrow Edge – Try it out instantly. No login, no friction

✅ MDM Support – Want more control in enterprise? You can control Sparrow with Group Policies!

New Features:

✅ Active Sync – Real-time Swagger/localhost collection syncing

✅ Postman Collection Import – Bring your existing workflow with you

✅ Public Workspaces – Collaborate and share instantly

✅ Sparrow Marketplace – Discover plug-and-play public APIs

✅ Mock Servers – Instant testing environments, no setup needed

✅ Expanded Protocol Support – GraphQL, WebSockets, Socket.IO & more

AI & Sparrow:

✅ LLM Debugging, Test Flows & Expressions – Build and troubleshoot as you go

✅ Sparrow AI Bot – Write API calls in plain English; powered by LLM of your choice, DeepSeek, Claude or OpenAI;

✅ AI Co-pilot & LLM Bot Management – Custom agents for seamless flow

✅ Auto-generate cURL, Docs, and Mock Data – No manual effort required

All in under 40MB, launching in around 1 second or less.

Whether you're shipping solo or scaling with teams across the globe, Sparrow delivers the power with the simplicity of a modern UI.

Now listed on AWS and Azure Marketplaces—ready when you are.

Experience API testing the way it should be.

— Team Sparrow | Try Now at https://sparrowapp.dev

Star Us on GitHub - https://github.com/sparrowapp-dev/sparrow-app

What can Sparrow do that Postman cannot and why should I switch?

Sparrow feels like the API tool we’ve all been waiting for — minimal, powerful, and built with real developer workflows in mind.

The blazing-fast startup time (under 1 second?!) paired with deep features like real-time Swagger sync, mock servers, and AI-assisted debugging makes this feel like the API tool we’ve actually been waiting for.

Also love the flexibility—REST, GraphQL, WebSockets, and even Socket.IO, all in one place. And the fact that you can self-host or use Sparrow Edge without login is a huge plus for both speed and security.

It’s a serious upgrade for modern dev workflows.

Lighter, Better and Faster. Sparrow v2 packs everything that a developer needs for api testing, and more. Since our last release, the team has built a bunch of new features, but I’m personally most excited about,

1. The ability to spin up Mock Servers - Intuitive and Fast. Its seriously the fastest way to Mock APIs amongst all other tools.

2. Supercharged AI Copilot – With features like "Help Me Debug" and "Keep/Revert Changes", it’s not just another chatbot that only answers - its an interactive sidekick, that helps debug and modify your API on the go.

Sparrow was built with developers at its core, to simplify API testing without compromising on speed or usability. Because the best devs deserve the best tools in their arsenal. Meet your next-level upgrade.

Sparrow is redefining how we approach API development. From self-hosting options and blazing-fast startup to real-time Swagger syncing and AI-assisted debugging, Sparrow is packed with features that genuinely make dev workflows smoother and faster.

The addition of mock servers, public workspaces, protocol flexibility (REST, GraphQL, WebSockets, Socket.IO), and a powerful AI co-pilot really puts it ahead of the curve. And the fact that it launches under 40MB in a second? That’s not just fast—it’s game-changing.

If you haven’t tried it yet, now’s the time! Head to https://sparrowapp.dev and start exploring!

🚀 Sparrow v2 is here — Lighter, Faster, and Built for Devs.

🔥 Blazing-fast startup (under 1 sec)

🧪 REST, GraphQL, WebSockets & socket.io – all in one place

⚡ Spin up Mock Servers in seconds — the fastest mocking experience out there

🤖 AI Copilot that does more than chat — debug, edit, revert in real time

🔐 Self-host or use Sparrow Edge — no login, no bloat

Built from the ground up to simplify API testing without compromising on speed, power, or UX. If you’re building, debugging, or testing APIs — Sparrow v2 is your new favorite tool. #SparrowApp #DevTools #APItesting

API testing used to feel like a headache with unreliable APIs, rate limiting, and numerous setup issues. Most tools fell apart in production. An auto-scaling, and easy deploy make everything much smoother. Developers will thank you for this. Congrats on the launch.

Cooool. Looking forward to test it

Good job! Congrats on the launch！🚀

A great solution，connecting and testing so many apis is indeed time-consuming

Sparrow has come a long way from where we started! <3

Super excited to see a resilient, efficient and open-source offering that will help devs work on their APIs faster and effectively. Our usage numbers prove this where we see our users loving and using Sparrow daily and continuously. 😊

Congrats team! Currently building an API and I deeply know how can you help on that process. Wish you all the best here!!

Congrats on the launch of Sparrow! 🎉 The ability to self-host or use Sparrow Edge without login is impressive. How does the MDM support work for enterprises looking to manage Sparrow with group policies? Is it straightforward to set up?

Congrats on the launch Ashutosh! API testing has been a tedious thing and I do hope this tool is useful.

Interesting use case for AI, good job. Congrats for the launch!

Just checked out the new Sparrow—and wow, it’s a huge leap.

It’s lighter, faster, and now comes with AI baked in. The natural language API calls are a game changer (finally, no need to dig through docs just to test an endpoint). Clean UI, no fluff, and feels way more focused than most tools out there.

Haven’t deep-dived yet, but first impression: this might become my go-to for modern API testing.

Great to these type of Platform

A tool which build speed clarity, and control