head to head · open source
Insomnia vs NSwag
Insomnia has 40,021 GitHub stars, 2,365 forks, 874 open issues and last shipped yesterday. NSwag has 7,365 stars, 1,360 forks, 2,057 open issues and last shipped 11 days ago. Insomnia leads on adoption by 443% (40,021 vs 7,365 stars). Insomnia is written in TypeScript under Apache-2.0; NSwag is written in C# under MIT. Insomnia has attracted 6% as many forks as stars, NSwag 18%. Insomnia was the more recently maintained of the two, and both are self-hostable with no licence fee.
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 | NSwag | |
|---|---|---|
| GitHub stars | ★ 40K | ★ 7.4K |
| License | Apache-2.0 | MIT |
| Written in | TypeScript | C# |
| Last push | 2026-09-17 | 2026-09-07 |
| Forks | ⑂ 2.4K | ⑂ 1.4K |
| 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 NSwag if
- You want the NSwag feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches C#
- You evaluated both and NSwag 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 NSwag
NSwag is an MIT licensed Swagger/OpenAPI 2.0 and 3.0 toolchain written in C for .NET, ASP.NET Core, and TypeScript developers who need to generate OpenAPI specifications from ASP.NET Web API controllers and generate C or TypeScript clients from those specifications.
read the full NSwag overview →
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Frequently asked questions
Is Insomnia or NSwag more popular?
Insomnia has 40,021 GitHub stars and NSwag has 7,365. Insomnia has the larger community by that measure.
Are Insomnia and NSwag free?
Both are open source. Insomnia is licensed under Apache-2.0 and NSwag under MIT. Neither carries a licence fee.
What is the difference between Insomnia and NSwag?
Insomnia is written in TypeScript and NSwag in C#. 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 NSwag?
Choose Insomnia if you want the larger community (40,021 stars) or its Apache-2.0 licence terms. Choose NSwag if its feature set, stack or MIT licence fits better. Both are self-hostable.