Top Open Source API Clients Tools in 2026
A curated collection of the 10 best free and open-source API Clients tools in 2026. Compare features, GitHub stars, tech stacks, and self-hosted software.
Yaak
Local-first API client for HTTP, GraphQL, gRPC, and more
Stars19,117Last commit12d agoLicenseMIT
BleachBit
Open-source disk cleaner and privacy manager
Stars6,719Last commit11d agoLicenseGPL-3.0
Voiden
Offline Git-native API workspace
Stars1,586Last commit26d agoLicenseApache-2.0
Bruno
Git-native API client for REST, GraphQL, gRPC and WebSocket
Stars46,580Last commit10d agoLicenseMIT
Requestly
Git-native API client for teams to design, build and test APIs
Stars6,750Last commit1mo agoLicenseOpen SourceInsomnia
Intuitive API client for REST, GraphQL, and gRPC. Debug, test, and collaborate on APIs with ease across platforms.
Stars39,956Last commit10d agoLicenseApache-2.0
HTTPie
Human-friendly API testing client for developers
Stars4,031Last commit17mo agoLicenseOpen SourceHoppscotch
Open-source API development ecosystem
Stars80,103Last commit1mo agoLicenseMITFirecamp
All-in-one platform for API testing, documentation, and collaboration, simplifying the entire API development lifecycle.
Stars2,608Last commit6mo agoLicenseAGPL-3.0ClassroomIO
All-in-one platform for customer, partner, and employee training
Stars1,661Last commit10d agoLicenseAGPL-3.0
