head to head · open source
Insomnia vs ATAC
Insomnia has 40,021 GitHub stars, 2,365 forks, 874 open issues and last shipped yesterday. ATAC has 3,729 stars, 137 forks, 20 open issues and last shipped 15 days ago. Insomnia leads on adoption by 973% (40,021 vs 3,729 stars). Insomnia is written in TypeScript under Apache-2.0; ATAC is written in Rust under MIT. Insomnia has attracted 6% as many forks as stars, ATAC 4%. Insomnia was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 2 topic tags (api, 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 | ATAC | |
|---|---|---|
| GitHub stars | ★ 40K | ★ 3.7K |
| License | Apache-2.0 | MIT |
| Written in | TypeScript | Rust |
| Last push | 2026-09-17 | 2026-09-03 |
| Forks | ⑂ 2.4K | ⑂ 137 |
| 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 ATAC if
- You want the ATAC feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches Rust
- You evaluated both and ATAC 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 ATAC
ATAC is a terminal API client written in Rust and licensed under MIT. It lives in the developer tools and API development and testing ecosystem, and it targets users who want a Postman like workflow without leaving a terminal. The project describes itself as Arguably a Terminal API Client, and it is based on clients such as Postman, Insomnia, and Bruno.
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Frequently asked questions
Is Insomnia or ATAC more popular?
Insomnia has 40,021 GitHub stars and ATAC has 3,729. Insomnia has the larger community by that measure.
Are Insomnia and ATAC free?
Both are open source. Insomnia is licensed under Apache-2.0 and ATAC under MIT. Neither carries a licence fee.
What is the difference between Insomnia and ATAC?
Insomnia is written in TypeScript and ATAC in Rust. 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 ATAC?
Choose Insomnia if you want the larger community (40,021 stars) or its Apache-2.0 licence terms. Choose ATAC if its feature set, stack or MIT licence fits better. Both are self-hostable.