pytest vs Mocha

Free and open source

Free and open source

Free and open source. You pay in engineering time and CI minutes.

Free and open source. You pay in engineering time and CI minutes.

Everything, self-hosted

Everything, self-hosted

Category standard

pytest-dev · since 2004

Widely used

OpenJS Foundation · since 2011

• Fixtures are the best dependency-injection model in any test framework, and they compose cleanly.
• Assertion introspection produces genuinely useful failure output from a plain assert.
• Vast plugin ecosystem — pytest-xdist, pytest-cov, pytest-asyncio, pytest-django.

• Small, stable and predictable — it does one job and has done it the same way for years.
• Pick your own assertions, mocks and coverage rather than accepting a bundle.
• Excellent async and reporter support.

• Fixture scope and ordering become genuinely hard to reason about in large suites.
• The magic that makes simple cases elegant makes complex cases opaque.
• Python only.

• No built-in mocking, snapshots, coverage or parallel-by-default execution.
• Assembling and documenting the stack is work every new project repeats.
• Fewer new projects adopt it; momentum sits with Vitest and Jest.

Essentially every Python project.

Node.js services where you want explicit control over every part of the test stack.