head to head · open source
Insomnia vs hey-api
Insomnia has 40,021 GitHub stars, 2,365 forks, 874 open issues and last shipped yesterday. hey-api has 5,416 stars, 434 forks, 630 open issues and last shipped 25 days ago. Insomnia leads on adoption by 639% (40,021 vs 5,416 stars). Insomnia is written in TypeScript under Apache-2.0; hey-api is written in TypeScript under MIT. Insomnia has attracted 6% as many forks as stars, hey-api 8%. Insomnia was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (api-client), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| Insomnia | hey-api | |
|---|---|---|
| GitHub stars | ★ 40K | ★ 5.4K |
| License | Apache-2.0 | MIT |
| Written in | TypeScript | TypeScript |
| Last push | 2026-09-17 | 2026-08-24 |
| Forks | ⑂ 2.4K | ⑂ 434 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Insomnia if
- You weight community size — 40K stars and counting
- You want the Apache-2.0 license terms
- Your stack matches TypeScript
- You value the larger contributor base for long-term maintenance
pick hey-api if
- You want the hey-api feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches TypeScript
- You evaluated both and hey-api fits your workflow better
About Insomnia
Insomnia is an open source, cross platform API client built with Electron and TypeScript for developing and testing APIs across multiple protocols including REST, GraphQL, WebSockets, SSE, and gRPC. It runs on macOS, Windows, and Linux and is distributed under the Apache 2.0 license. The project serves as a direct open source alternative to Postman, offering similar core functionality without vendor lock in or mandatory cloud usage.
read the full Insomnia overview →
About hey-api
Hey API is an open source ecosystem for turning API specifications into production ready code. It is distributed as a monorepo containing all of the project's open source packages, with the two primary generators being openapi ts for TypeScript and openapi python for Python. The TypeScript generator ships with more than twenty plugins covering SDKs, Zod schemas, and TanStack Query hooks, while the Python generator produces SDKs and Pydantic models. A supporting library, spec types , provides TypeScript definitions for OpenAPI and JSON Schema specifications with complete inline documentation. The project lives in …
read the full hey-api overview →
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Frequently asked questions
Is Insomnia or hey-api more popular?
Insomnia has 40,021 GitHub stars and hey-api has 5,416. Insomnia has the larger community by that measure.
Are Insomnia and hey-api free?
Both are open source. Insomnia is licensed under Apache-2.0 and hey-api under MIT. Neither carries a licence fee.
What is the difference between Insomnia and hey-api?
Insomnia is written in TypeScript and hey-api in TypeScript. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Insomnia or hey-api?
Choose Insomnia if you want the larger community (40,021 stars) or its Apache-2.0 licence terms. Choose hey-api if its feature set, stack or MIT licence fits better. Both are self-hostable.