Best Open-source API Clients & Testing tools

Explore curated open-source tools in the API Clients & Testing category. Compare technologies, see alternatives, and find the right solution for your workflow.

10+ projects · Page 1 of 1

Yaak logo

Yaak

Fast, privacy-first desktop API client for modern protocols

Stars
18,886
License
MIT
Last commit
3 hours ago
TypeScriptActive
Scalar logo

Scalar

Instant, offline‑first OpenAPI client with modern interactive docs

Stars
15,662
License
MIT
Last commit
3 hours ago
TypeScriptActive
Insomnia logo

Insomnia

Cross-platform API client for REST, GraphQL, gRPC, and more

Stars
39,898
License
Apache-2.0
Last commit
5 hours ago
TypeScriptActive
Bruno logo

Bruno

Local‑first API client that stores collections as plain files

Stars
45,783
License
MIT
Last commit
7 hours ago
JavaScriptActive
Hurl logo

Hurl

Run and test HTTP requests from a single fast CLI

Stars
19,084
License
Apache-2.0
Last commit
12 hours ago
RustActive
Requestly logo

Requestly

Local-first API client, interceptor, and mocking platform.

Stars
6,742
License
Last commit
16 hours ago
Active
Hoppscotch logo

Hoppscotch

Lightweight API development ecosystem for testing and collaboration

Stars
79,847
License
MIT
Last commit
1 day ago
TypeScriptActive
API Dash logo

API Dash

Beautiful cross-platform API client with multimedia response preview

Stars
2,856
License
Apache-2.0
Last commit
11 days ago
DartActive
Restfox logo

Restfox

Offline-First HTTP & Socket Testing Client for Web & Desktop

Stars
2,730
License
MIT
Last commit
18 days ago
VueActive
Cartero logo

Cartero

Native graphical HTTP client for testing APIs freely

Stars
1,024
License
GPL-3.0
Last commit
1 month ago
RustActive
Pororoca logo

Pororoca

HTTP testing tool with HTTP/2, HTTP/3, and WebSocket support

Stars
660
License
Last commit
1 month ago
C#Active
ATAC logo

ATAC

Terminal-based API client for free, offline HTTP testing

Stars
3,678
License
MIT
Last commit
4 months ago
RustStable
Firecamp logo

Firecamp

Developer-first multi-protocol API platform with VSCode-inspired experience

Stars
2,600
License
AGPL-3.0
Last commit
4 months ago
TypeScriptStable
Curlie logo

Curlie

Curlie: curl’s power with httpie’s friendly syntax

Stars
3,697
License
MIT
Last commit
7 months ago
GoStable
Yaade logo

Yaade

Self-hosted, collaborative API development environment with multi-user support

Stars
1,985
License
MIT
Last commit
10 months ago
JavaScriptStable
HTTPie logo

HTTPie

Human-friendly command-line HTTP client for the API era

Stars
38,328
License
BSD-3-Clause
Last commit
1 year ago
PythonDormant
Ezy logo

Ezy

Desktop gRPC and gRPC-Web client for API testing

Stars
1,038
License
MPL-2.0
Last commit
2 years ago
TypeScriptDormant
Prestige logo

Prestige

In-browser, text-driven HTTP client for rapid API testing.

Stars
402
License
Apache-2.0
Last commit
3 years ago
TypeScriptDormant