pytest vs Jest

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

Category standard

OpenJS Foundation · since 2014

• 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.

• Everything in one dependency, with defaults that work for most projects on day one.
• The largest ecosystem of matchers, reporters and framework presets in JavaScript.
• Snapshot testing is genuinely useful for serialisable output when used with restraint.

• 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.

• Native ESM support remains awkward, and the Babel transform layer is a recurring configuration tax.
• Noticeably slower than Vitest on large suites.
• jsdom is not a browser; subtle DOM and CSS behaviour differs from reality.

Essentially every Python project.

Existing JavaScript codebases, React Native, and teams that value ecosystem depth over raw speed.