head to head · open source
Bruno vs greenmail
Bruno has 47,022 GitHub stars, 2,888 forks, 1,831 open issues and last shipped yesterday. greenmail has 744 stars, 204 forks, 67 open issues and last shipped yesterday. Bruno leads on adoption by 6,220% (47,022 vs 744 stars). Bruno is written in JavaScript under MIT; greenmail is written in Java under Apache-2.0. Bruno has attracted 6% as many forks as stars, greenmail 27%. Bruno was the more recently maintained of the two, and both are self-hostable with no licence fee.
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 | greenmail | |
|---|---|---|
| GitHub stars | ★ 47K | ★ 744 |
| License | MIT | Apache-2.0 |
| Written in | JavaScript | Java |
| Last push | 2026-09-17 | 2026-09-17 |
| Forks | ⑂ 2.9K | ⑂ 204 |
| 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 greenmail if
- You want the greenmail 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 greenmail 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 greenmail
GreenMail is a Java project that provides a virtual mail server for testing email based applications, services, and systems. It is Apache 2.0 licensed, published through Maven Central as com.icegreen:greenmail, and listed in Developer Tools / API Development & Testing.
read the full greenmail overview →
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Frequently asked questions
Is Bruno or greenmail more popular?
Bruno has 47,022 GitHub stars and greenmail has 744. Bruno has the larger community by that measure.
Are Bruno and greenmail free?
Both are open source. Bruno is licensed under MIT and greenmail under Apache-2.0. Neither carries a licence fee.
What is the difference between Bruno and greenmail?
Bruno is written in JavaScript and greenmail 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, Bruno or greenmail?
Choose Bruno if you want the larger community (47,022 stars) or its MIT licence terms. Choose greenmail if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.