Hypothesis

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About

Hypothesis is ranked #7 of 27 in property-based testing tools on Inferse. It runs on Linux, macOS, Windows.

Compared on property-based testing tools

Free plan: Yeshypothesis.works
Supported languages: Pythonhypothesis.works
Test runner support: pytest, unittesthypothesis.works
Failing-case shrinking: Yeshypothesis.works
Stateful testing: Yeshypothesis.works
Reproducible failures: Yeshypothesis.works

Facts

What it does: Hypothesis is a property-based testing library for Python that generates inputs, including edge cases, to test properties you describe.hypothesis.works · 28 Sept 2026
Simplifies failures: When Hypothesis finds a bug, it reports a failing example and tries to simplify it.hypothesis.works · 28 Sept 2026
Test framework support: Hypothesis works with pytest, unittest, nose, or another framework that can run a Python function.hypothesis.works · 28 Sept 2026
Data generation: Its strategies let users describe and compose the kinds of data their tests should generate.hypothesis.works · 28 Sept 2026
Repeatable failures: Hypothesis saves failing examples in a local test database so it can replay them when tests run again.hypothesis.works · 28 Sept 2026
Test runner limitation: Hypothesis is not itself a test runner; it works inside a user's normal testing framework.hypothesis.works · 28 Sept 2026
Thread safety: As of version 6.136.9, Hypothesis supports running the same test simultaneously from multiple threads.hypothesis.works · 28 Sept 2026
Release availability: The project describes publishing new packages to PyPI after changes are merged, usually within half an hour.hypothesis.works · 28 Sept 2026
Intended users: Hypothesis is for people writing software tests who want to describe acceptable behavior and have the computer explore inputs.hypothesis.works · 28 Sept 2026
Edge cases: Hypothesis randomly chooses inputs, including edge cases the user may not have considered.hypothesis.works · 29 Sept 2026
Test runners: Hypothesis tests can run as regular Python functions and work with pytest or unittest.hypothesis.readthedocs.io · 29 Sept 2026
Default run count: By default, Hypothesis generates 100 random inputs per test, and this count can be controlled with the max_examples setting.hypothesis.readthedocs.io · 29 Sept 2026
Integrations: First-party extras include integrations for specific packages, and the documentation gives Django as an example installable extra.hypothesis.readthedocs.io · 29 Sept 2026
Operating systems: The project says it is known to work and regularly tested on macOS, Windows, Linux, and Emscripten.hypothesis.readthedocs.io · 29 Sept 2026
Python support: Hypothesis is supported and tested on CPython and PyPy 3.10 and later.hypothesis.readthedocs.io · 29 Sept 2026
Community help: Users can ask questions using the python-hypothesis Stack Overflow tag or join the mailing list for help and discussion.hypothesis.readthedocs.io · 29 Sept 2026
Compatibility limit: The project supports only the most recent Hypothesis version; documented APIs are not expected to break except between major version bumps, while undocumented behavior may break in patch releases.hypothesis.readthedocs.io · 29 Sept 2026
Development model: The maintainers say new features must be sponsored or implemented by someone else, and the project has no long-term release plan.hypothesis.readthedocs.io · 29 Sept 2026