head to head · open source
Bruno vs OpenAPI-Specification
Bruno has 47,022 GitHub stars, 2,888 forks, 1,831 open issues and last shipped yesterday. OpenAPI-Specification has 31,215 stars, 9,156 forks, 80 open issues and last shipped 7 days ago. Bruno leads on adoption by 51% (47,022 vs 31,215 stars). Bruno is written in JavaScript under MIT; OpenAPI-Specification is written in Markdown under Apache-2.0. Bruno has attracted 6% as many forks as stars, OpenAPI-Specification 29%. Bruno was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (openapi), 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
| Bruno | OpenAPI-Specification | |
|---|---|---|
| GitHub stars | ★ 47K | ★ 31K |
| License | MIT | Apache-2.0 |
| Written in | JavaScript | Markdown |
| Last push | 2026-09-17 | 2026-09-11 |
| Forks | ⑂ 2.9K | ⑂ 9.2K |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Bruno if
- You weight community size — 47K stars and counting
- You want the MIT license terms
- Your stack matches JavaScript
- You value the larger contributor base for long-term maintenance
pick OpenAPI-Specification if
- You want the OpenAPI-Specification feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Markdown
- You evaluated both and OpenAPI-Specification fits your workflow better
About Bruno
Bruno is a lightweight, open source API client and IDE for exploring and testing APIs, built for developers and teams who want their request collections stored as plain text in a folder on their own filesystem rather than in a vendor's cloud.
read the full Bruno overview →
About OpenAPI-Specification
The OpenAPI Specification (OAS) is a community driven open specification hosted within the OpenAPI Initiative, a Linux Foundation Collaborative Project. It defines a standard, programming language agnostic interface description for HTTP APIs, represented in YAML or JSON. The specification lives in the HTTP API tooling ecosystem, alongside the tools, libraries, and implementations listed in the repository's implementations document. The project source is released under the Apache 2.0 license, and its GitHub repository has accumulated roughly 31,000 stars and 9,100 forks across 13 years of activity.…
read the full OpenAPI-Specification overview →
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Frequently asked questions
Is Bruno or OpenAPI-Specification more popular?
Bruno has 47,022 GitHub stars and OpenAPI-Specification has 31,215. Bruno has the larger community by that measure.
Are Bruno and OpenAPI-Specification free?
Both are open source. Bruno is licensed under MIT and OpenAPI-Specification under Apache-2.0. Neither carries a licence fee.
What is the difference between Bruno and OpenAPI-Specification?
Bruno is written in JavaScript and OpenAPI-Specification in Markdown. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Bruno or OpenAPI-Specification?
Choose Bruno if you want the larger community (47,022 stars) or its MIT licence terms. Choose OpenAPI-Specification if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.