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

Hurl logo

Hurl

Run and test HTTP requests from a single fast CLI

Stars
18,990
License
Apache-2.0
Last commit
8 hours ago
RustActive
Insomnia logo

Insomnia

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

Stars
38,477
License
Apache-2.0
Last commit
21 hours ago
TypeScriptActive
Scalar logo

Scalar

Instant, offline‑first OpenAPI client with modern interactive docs

Stars
15,195
License
MIT
Last commit
23 hours ago
TypeScriptActive
Hoppscotch logo

Hoppscotch

Lightweight API development ecosystem for testing and collaboration

Stars
79,444
License
MIT
Last commit
1 day ago
TypeScriptActive
Bruno logo

Bruno

Local‑first API client that stores collections as plain files

Stars
44,722
License
MIT
Last commit
1 day ago
JavaScriptActive
Yaak logo

Yaak

Fast, privacy-first desktop API client for modern protocols

Stars
18,726
License
MIT
Last commit
2 days ago
TypeScriptActive
Pororoca logo

Pororoca

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

Stars
659
License
Last commit
3 days ago
C#Active
Requestly logo

Requestly

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

Stars
6,725
License
Last commit
3 days ago
Active
API Dash logo

API Dash

Beautiful cross-platform API client with multimedia response preview

Stars
2,833
License
Apache-2.0
Last commit
20 days ago
DartActive
Restfox logo

Restfox

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

Stars
2,710
License
MIT
Last commit
1 month ago
VueActive
Cartero logo

Cartero

Native graphical HTTP client for testing APIs freely

Stars
1,008
License
GPL-3.0
Last commit
2 months ago
RustActive
ATAC logo

ATAC

Terminal-based API client for free, offline HTTP testing

Stars
3,633
License
MIT
Last commit
2 months ago
RustActive
Firecamp logo

Firecamp

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

Stars
2,597
License
AGPL-3.0
Last commit
3 months ago
TypeScriptStable
Curlie logo

Curlie

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

Stars
3,659
License
MIT
Last commit
6 months ago
GoStable
Yaade logo

Yaade

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

Stars
1,986
License
MIT
Last commit
9 months ago
JavaScriptStable
HTTPie logo

HTTPie

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

Stars
38,200
License
BSD-3-Clause
Last commit
1 year ago
PythonDormant
Ezy logo

Ezy

Desktop gRPC and gRPC-Web client for API testing

Stars
1,041
License
MPL-2.0
Last commit
2 years ago
TypeScriptDormant
Prestige logo

Prestige

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

Stars
403
License
Apache-2.0
Last commit
3 years ago
TypeScriptDormant