Best Open Source API Clients using CodeMirror in 2026

Hoppscotch

Sleek, intuitive API development and testing platform

Stars
79,107
Forks
5,855
Last commit
10 hours ago

Lightweight, fast, and feature-rich API client for developers. Test, debug, and document APIs with ease in a clean, modern interface.

Open Source Alternative to:

Postman

Bruno

Lightweight, fast, and open-source API client for developers

Stars
43,503
Forks
2,380
Last commit
10 hours ago

A modern, user-friendly API client that simplifies API testing and development with a clean interface and powerful features.

Open Source Alternative to:

Postman

Insomnia

Powerful API development and testing made effortless

Stars
38,376
Forks
2,283
Last commit
10 hours ago

Intuitive API client for REST, GraphQL, and gRPC. Debug, test, and collaborate on APIs with ease across platforms.

Open Source Alternative to:

Postman

Yaak

Fast, secure, offline API client with Git integration

Stars
18,529
Forks
747
Last commit
5 days ago

A modern API client offering local-only data storage, Git integration, plugin extensibility, and multi-protocol support for developers.

Open Source Alternative to:

Postman

Requestly

Intercept, modify, and debug HTTP(S) requests effortlessly

Stars
6,681
Forks
644
Last commit
2 days ago

A powerful browser extension and desktop app for developers to manipulate network requests, debug APIs, and improve web app testing

Open Source Alternative to:

Postman

Firecamp

Unified API development ecosystem for modern teams

Stars
2,593
Forks
167
Last commit
2 months ago

All-in-one platform for API testing, documentation, and collaboration, simplifying the entire API development lifecycle.

Open Source Alternative to:

Postman

Voiden

Build APIs like code with Git-native workspace

Stars
953
Forks
30
Last commit
18 hours ago

Offline-first API workspace that unifies specs, docs, tests, and mocks in programmable Markdown blocks. Version control everything in plain text files.

Open Source Alternative to:

Postman

Stars
Forks
Last commit

Stars
Forks
Last commit

Stars
Forks
Last commit

Stars
Forks
Last commit

Stars
Forks
Last commit

Stars
Forks
Last commit

Hoppscotch

Sleek, intuitive API development and testing platform

Stars
79,107
Forks
5,855
Last commit
10 hours ago

Lightweight, fast, and feature-rich API client for developers. Test, debug, and document APIs with ease in a clean, modern interface.

Open Source Alternative to:

Postman

Bruno

Lightweight, fast, and open-source API client for developers

Stars
43,503
Forks
2,380
Last commit
10 hours ago

A modern, user-friendly API client that simplifies API testing and development with a clean interface and powerful features.

Open Source Alternative to:

Postman

Insomnia

Powerful API development and testing made effortless

Stars
38,376
Forks
2,283
Last commit
10 hours ago

Intuitive API client for REST, GraphQL, and gRPC. Debug, test, and collaborate on APIs with ease across platforms.

Open Source Alternative to:

Postman

Yaak

Fast, secure, offline API client with Git integration

Stars
18,529
Forks
747
Last commit
5 days ago

A modern API client offering local-only data storage, Git integration, plugin extensibility, and multi-protocol support for developers.

Open Source Alternative to:

Postman

Requestly

Intercept, modify, and debug HTTP(S) requests effortlessly

Stars
6,681
Forks
644
Last commit
2 days ago

A powerful browser extension and desktop app for developers to manipulate network requests, debug APIs, and improve web app testing

Open Source Alternative to:

Postman

Firecamp

Unified API development ecosystem for modern teams

Stars
2,593
Forks
167
Last commit
2 months ago

All-in-one platform for API testing, documentation, and collaboration, simplifying the entire API development lifecycle.

Open Source Alternative to:

Postman

Voiden

Build APIs like code with Git-native workspace

Stars
953
Forks
30
Last commit
18 hours ago

Offline-first API workspace that unifies specs, docs, tests, and mocks in programmable Markdown blocks. Version control everything in plain text files.

Open Source Alternative to:

Postman

Open Source API Clients using CodeMirror

A curated collection of the best open source client applications for interacting with and testing APIs. using CodeMirror.