Written by the Apidog team. Apidog is not open source, and this page says so up front; the last section explains where it fits next to these tools. Licenses and prices were checked on each project's repository and site on September 8, 2026.
"Open source" gets attached to a lot of API clients that are only partly open, so this list is strict about it: every tool below has its client code under an OSI-approved license, and the license is named. Where a company sells a hosted or paid tier on top, that is noted too, because the paid tier is usually where team features live.
The 10 at a glance
| Tool | License | Stars (approx.) | Form | Paid tier |
|---|---|---|---|---|
| Bruno | MIT | 47,000 | Desktop, files in Git | Pro $6/user/month; Ultimate $11 |
| Hoppscotch | MIT | 80,000 | Browser, desktop, self-host | Organization $6/user/month |
| Insomnia | Apache 2.0 | 40,000 | Desktop | Pro $12/user/month; Enterprise $45 |
| Yaak | MIT | Desktop, local-first | $79/year commercial; Business $149/user/year | |
| HTTPie CLI | BSD-3-Clause | 38,500 | Terminal | Desktop app |
| Hurl | Apache 2.0 | 19,000 | Terminal, plain-text test files | None |
| Posting | Apache 2.0 | 12,000 | Terminal UI | None |
| Restfox | MIT | 2,800 | Web and desktop, offline-first | None |
| API Dash | Apache 2.0 | 2,900 | Desktop (Flutter) | None |
| Scalar API client | MIT | Web and desktop | Docs platform from $150/month |
1. Bruno (MIT)
Bruno keeps every request as a .bru text file inside your repository, so collections are versioned, diffed, and reviewed like code. It works fully offline and needs no account. The free client is complete; Pro ($6 per user per month) adds in-app Git integration, an unlimited collection runner, and code generation, and Ultimate ($11) adds SSO, SCIM, and audit logs.
Limit: anything that needs a shared server. No real-time co-editing, no hosted mock, no published docs, and OpenAPI sync is capped at five a month on Pro. Details in Bruno limitations.
2. Hoppscotch (MIT)
The zero-install option. Hoppscotch runs in a browser tab, ships desktop apps, and can be self-hosted from the repository inside your own network. The free plan states no caps on workspaces, collections, requests, or runners; Organization is $6 per user.
Limit: requests to localhost need the desktop app or a browser extension, docs publishing is thin, mocking is new, and there is no scenario testing with database steps. See Postman vs Hoppscotch.
3. Insomnia (Apache 2.0)
The most established open-source desktop client, maintained by Kong. REST, GraphQL, gRPC, WebSockets, and SSE in one app, with projects stored locally, in Git, or in Kong's cloud. Free includes Git Sync for up to three users and 1,000 mock requests a month.
Limit: design, tests, mocks, and docs are separate features, mocks are metered on Free, and Pro is $12 per user. See Postman vs Insomnia.
4. Yaak (MIT)
A local-first desktop client that never stores, syncs, or transmits your data. Free for personal use; commercial use is $79 a year, $399 for a lifetime license, or $149 per user per year on the Business plan with SSO. Covers REST, GraphQL, gRPC, WebSockets, and SSE.
Limit: no sync and no team features of any kind. See what is Yaak.
5. HTTPie CLI (BSD-3-Clause)
The terminal client most people reach for when curl output gets tiring: JSON by default, colored output, sessions, downloads, and plugins. The CLI is BSD-licensed; the company also ships a desktop app.
Limit: it sends requests. Collections, mocks, docs, and test scenarios are someone else's job.
6. Hurl (Apache 2.0)
Hurl runs HTTP requests defined in a plain-text file, chains them, captures values, and asserts on responses, which makes it a good fit for CI. It handles REST, SOAP, and GraphQL and is maintained by Orange.
Limit: no GUI, no mocks, no docs. It is a test runner, and a good one; the comparison with other runners is in Postman CLI alternatives.
7. Posting (Apache 2.0)
A keyboard-driven HTTP client that lives in the terminal, with requests stored as YAML files you can commit. If you work over SSH or never leave tmux, this is the one.
Limit: single-user by design, no mocks, no docs, no team layer.
8. Restfox (MIT)
An offline-first, minimal HTTP and socket client that runs on the web or as a desktop app, with a Postman-like layout.
Limit: small project, no team features, no mocks or docs.
9. API Dash (Apache 2.0)
A cross-platform desktop client built with Flutter, with HTTP and GraphQL requests, code generation for many languages, and AI-assisted features.
Limit: early-stage compared with the tools above; no collaboration, mocks, or docs.
10. Scalar API client (MIT)
Scalar's client is open source on web, macOS, Linux, and Windows, and it sits next to Scalar's OpenAPI reference renderer, which is the strongest docs output on this list. The docs platform is a paid product (Free covers three APIs; Pro is $150 a month).
Limit: testing and mocking are not first-class in the client, and the platform's pricing scales by API count. See Apidog vs Scalar.
What every open-source client leaves to you
The pattern across all ten is the same. The client is open and often excellent; the shared layer is either missing or paid. Real-time co-editing, a hosted mock that a frontend team can hit, a published docs site, scenario tests with data tables and database steps, and enterprise controls like SSO, SCIM, and audit logs are where these projects either stop or start charging. For a solo developer that does not matter. For a team, it usually decides the choice.
Where Apidog fits
Apidog is not open source, so if an OSI license is a hard requirement, pick from the ten above and stop here. If the requirement behind "open source" is really cost or control, Apidog answers both differently:
- Cost: the free plan covers four users with unlimited test runs and mock calls; paid seats start at $9 per user per month, below Postman's $19 Team seat and Insomnia's $12 Pro.
- Control: an EU-hosted instance, a self-hosted runner that executes tests and mocks inside your network, and an on-premises edition of the whole platform.
- The shared layer the clients above lack: two people editing the same spec at once, mocks generated from the response schema, scenario tests with SQL steps that run in GitHub Actions, GitLab CI, and Jenkins through the CLI, and docs published from the same spec. Postman
pm.*scripts run unchanged after import.
Most teams we see end up with one open-source client for individual work and Apidog as the shared project, importing OpenAPI from Bruno or Hoppscotch when the work needs mocks, docs, or CI. The migration path is in how to migrate from Postman to Apidog, and the wider comparison of all eight mainstream Postman alternatives is in Postman alternatives in 2026.
FAQ
What is the best open-source Postman alternative? Bruno for Git-first work, Hoppscotch for zero-install, Insomnia for the most mature desktop feature set.
Is Apidog open source? No. The desktop apps, web app, CLI, and runner are free to use but not open source. The free plan covers four users.
Which open-source Postman alternative can I self-host? Hoppscotch, from its repository. Bruno, Yaak, Restfox, Posting, and the terminal tools are local and need no server.
Which one runs Postman collections in CI? Hurl and the HTTPie CLI for scripted checks, Bruno's CLI on Pro, or the Apidog CLI for scenario suites; the runners are compared in Postman CLI alternatives.
Do these tools import Postman collections? Bruno, Hoppscotch, Insomnia, Yaak, and Apidog import Postman JSON. Hurl and Posting use their own text formats, and Apidog is the only one on this page that runs pm.* scripts as they are.
Licenses and prices were checked on September 8, 2026.
