Best API Clients & Testing Tools

Explore leading tools in the API Clients & Testing category, including open-source options and SaaS products. Compare features, use cases, and find the best fit for your workflow.

10+ open-source projects · 8 SaaS products

Top open-source API Clients & Testing

These projects are active, self-hostable choices for knowledge management teams evaluating alternatives to SaaS tools.

View all 10+ open-source options
Hoppscotch logo

Hoppscotch

Lightweight API development ecosystem for testing and collaboration

Stars
77,605
License
MIT
Last commit
23 hours ago
TypeScriptActive
Bruno logo

Bruno

Local‑first API client that stores collections as plain files

Stars
40,098
License
MIT
Last commit
1 day ago
JavaScriptActive
Insomnia logo

Insomnia

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

Stars
37,828
License
Apache-2.0
Last commit
1 day ago
TypeScriptActive
Hurl logo

Hurl

Run and test HTTP requests from a single fast CLI

Stars
18,400
License
Apache-2.0
Last commit
1 day ago
RustActive
Yaak logo

Yaak

Fast, privacy-first desktop API client for modern protocols

Stars
17,461
License
MIT
Last commit
1 day ago
TypeScriptActive
Scalar logo

Scalar

Instant, offline‑first OpenAPI client with modern interactive docs

Stars
13,539
License
MIT
Last commit
23 hours ago
TypeScriptActive
Most starred project
77,605★

Lightweight API development ecosystem for testing and collaboration

Recently updated
23 hours ago

Fast, minimalistic platform for building, testing, and documenting REST, GraphQL, WebSocket, and real-time APIs with team collaboration and cloud sync.

Dominant language
TypeScript • 5 projects

Expect a strong TypeScript presence among maintained projects.

Popular SaaS Platforms to Replace

Understand the commercial incumbents teams migrate from and how many open-source alternatives exist for each product.

View all 8 SaaS options
Apidog logo

Apidog

All-in-one API platform to design, debug, mock, and test with CI/CD

API Clients & Testing
Alternatives tracked
18 alternatives
BlazeMeter logo

BlazeMeter

Continuous testing platform for performance, API, and functional testing at scale

API Clients & Testing
Alternatives tracked
18 alternatives
Insomnia logo

Insomnia

Collaborative API development platform for building and testing APIs

API Clients & Testing
Alternatives tracked
18 alternatives
Postman logo

Postman

API development and testing platform

API Clients & Testing
Alternatives tracked
18 alternatives
RapidAPI for Mac logo

RapidAPI for Mac

Native macOS HTTP client for API development and testing

API Clients & Testing
Alternatives tracked
18 alternatives
ReadyAPI logo

ReadyAPI

Enterprise API testing suite for functional, security, performance, and virtualization

API Clients & Testing
Alternatives tracked
18 alternatives
Most compared product
10+ open-source alternatives

Apidog combines visual API design, interactive docs, automated testing, and mocking in a single workspace, with integrations for pipelines.

Leading hosted platforms

Frequently replaced when teams want private deployments and lower TCO.

Explore related categories

Browse neighbouring categories in DevOps & Platform to widen your evaluation.