head to head · open source
Harness vs pytest-testmon
Harness has 38,798 GitHub stars, 3,451 forks, 106 open issues and last shipped yesterday. pytest-testmon has 1,034 stars, 87 forks, 38 open issues and last shipped yesterday. Harness leads on adoption by 3,652% (38,798 vs 1,034 stars). Harness is written in Go under Apache-2.0; pytest-testmon is written in Python under MIT. Harness has attracted 9% as many forks as stars, pytest-testmon 8%. Harness was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (ci), 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
| Harness | pytest-testmon | |
|---|---|---|
| GitHub stars | ★ 39K | ★ 1.0K |
| License | Apache-2.0 | MIT |
| Written in | Go | Python |
| Last push | 2026-11-02 | 2026-11-02 |
| Forks | ⑂ 3.5K | ⑂ 87 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Harness if
- You weight community size — 39K stars and counting
- You want the Apache-2.0 license terms
- Your stack matches Go
- You value the larger contributor base for long-term maintenance
pick pytest-testmon if
- You want the pytest-testmon feature set and don't need the biggest community
- You prefer the MIT license terms
- Your stack matches Python
- You evaluated both and pytest-testmon fits your workflow better
About Harness
Harness Harness Open Source is an open source development platform packed with the power of code hosting, automated DevOps pipelines, hosted development environments (Gitspaces), and artifact registries. Overview Harness Open source is an open source development platform packed with the power of code hosting, automated DevOps pipelines, Gitspaces, and artifact registries. Running Harness locally The latest publicly released docker image can be found on harness/harness. To install Harness yourself, simply run the command below. Once the container is up, you can visit in your browser. The Harness image uses a…
read the full Harness overview →
About pytest-testmon
This is a pytest plug in which automatically selects and re executes only tests affected by recent changes. How is this possible in dynamic language like Python and how reliable is it? Read here: Determining affected tests Quickstart pip install pytest testmon build the dependency database and save it to .testmondata pytest testmon change some of your code (with test coverage) only run tests affected by recent changes pytest testmon To learn more about different options you can use with testmon, please head to testmon.org Call for opensource projects: try testmon in CI with no effort or risk. We would like to…
read the full pytest-testmon overview →
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Frequently asked questions
Is Harness or pytest-testmon more popular?
Harness has 38,798 GitHub stars and pytest-testmon has 1,034. Harness has the larger community by that measure.
Are Harness and pytest-testmon free?
Both are open source. Harness is licensed under Apache-2.0 and pytest-testmon under MIT. Neither carries a licence fee.
What is the difference between Harness and pytest-testmon?
Harness is written in Go and pytest-testmon in Python. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Harness or pytest-testmon?
Choose Harness if you want the larger community (38,798 stars) or its Apache-2.0 licence terms. Choose pytest-testmon if its feature set, stack or MIT licence fits better. Both are self-hostable.