head to head · open source
Insomnia vs swagger-core
Insomnia has 40,021 GitHub stars, 2,365 forks, 874 open issues and last shipped yesterday. swagger-core has 7,530 stars, 2,259 forks, 197 open issues and last shipped yesterday. Insomnia leads on adoption by 431% (40,021 vs 7,530 stars). Insomnia is written in TypeScript under Apache-2.0; swagger-core is written in Java under Apache-2.0. Insomnia has attracted 6% as many forks as stars, swagger-core 30%. Insomnia was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (rest-api), 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 | swagger-core | |
|---|---|---|
| GitHub stars | ★ 40K | ★ 7.5K |
| License | Apache-2.0 | Apache-2.0 |
| Written in | TypeScript | Java |
| Last push | 2026-09-17 | 2026-09-17 |
| Forks | ⑂ 2.4K | ⑂ 2.3K |
| 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 swagger-core if
- You want the swagger-core feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Java
- You evaluated both and swagger-core 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 swagger-core
Swagger Core is the Java implementation of the OpenAPI Specification that generates a machine readable REST API description from JAX RS2 annotations and Java classes, intended for Java server developers and API platform teams that publish and maintain OpenAPI documents alongside their services.
read the full swagger-core overview →
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Frequently asked questions
Is Insomnia or swagger-core more popular?
Insomnia has 40,021 GitHub stars and swagger-core has 7,530. Insomnia has the larger community by that measure.
Are Insomnia and swagger-core free?
Both are open source. Insomnia is licensed under Apache-2.0 and swagger-core under Apache-2.0. Neither carries a licence fee.
What is the difference between Insomnia and swagger-core?
Insomnia is written in TypeScript and swagger-core in Java. 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 swagger-core?
Choose Insomnia if you want the larger community (40,021 stars) or its Apache-2.0 licence terms. Choose swagger-core if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.