head to head · open source
Insomnia vs Scalar
Insomnia has 40,111 GitHub stars, 2,388 forks, 874 open issues and last shipped yesterday. Scalar has 16,364 stars, 964 forks, 75 open issues and last shipped yesterday. Insomnia leads on adoption by 145% (40,111 vs 16,364 stars). Insomnia is written in TypeScript under Apache-2.0; Scalar is written in TypeScript under MIT. Insomnia has attracted 6% as many forks as stars, Scalar 6%. Scalar was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 4 topic tags (api, api-client, http-client, 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 | Scalar | |
|---|---|---|
| GitHub stars | ★ 40K | ★ 16K |
| License | Apache-2.0 | MIT |
| Written in | TypeScript | TypeScript |
| Last push | 2026-11-02 | 2026-11-02 |
| Forks | ⑂ 2.4K | ⑂ 964 |
| 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 Scalar if
- You want the Scalar feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches TypeScript
- You evaluated both and Scalar fits your workflow better
About Insomnia
Insomnia API Client Insomnia is an open source, cross platform API client for GraphQL, REST, WebSockets, Server Sent Events (SSE), gRPC and any other HTTP compatible protocol. With Insomnia you can: Debug APIs using the most popular protocols and formats. Design APIs using the native OpenAPI editor and visual preview. Test APIs using native test suites and collection runner. Mock APIs using a cloud or self hosted mocking server. Build CI/CD pipelines using the native Insomnia CLI for linting and testing. Collaborate with others using the many collaboration features. And more including the ability to use 3rd…
read the full Insomnia overview →
About Scalar
Scalar Interactive API Reference from OpenAPI/Swagger └ Renders OpenAPI/Swagger documents └ Comes with an API testing tool └ Doesn't look like 2011 └ Generates code examples for many languages & frameworks └ Integrates with your favorite framework └ Try Demo An offline first API Client built for OpenAPI └ Free and open source └ First class OpenAPI/Swagger support └ Integrates with dozens of API Frameworks (Elysia, Hono, FastAPI, etc) └ Syncs with your favorite server framework (Watch Mode) └ Has environment variables, dynamic parameters and everything └ Try It in the Browser └ Download (Windows, MacOS, Linux)…
read the full Scalar overview →
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Frequently asked questions
Is Insomnia or Scalar more popular?
Insomnia has 40,111 GitHub stars and Scalar has 16,364. Insomnia has the larger community by that measure.
Are Insomnia and Scalar free?
Both are open source. Insomnia is licensed under Apache-2.0 and Scalar under MIT. Neither carries a licence fee.
What is the difference between Insomnia and Scalar?
Insomnia is written in TypeScript and Scalar 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 Scalar?
Choose Insomnia if you want the larger community (40,111 stars) or its Apache-2.0 licence terms. Choose Scalar if its feature set, stack or MIT licence fits better. Both are self-hostable.