RSpec 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

Widely used

RSpec Team · since 2005

Category standard

OpenJS Foundation · since 2014

• The output reads as documentation of intended behaviour.
• Shared examples and contexts keep large Rails suites organised.
• Deep integration with the Rails ecosystem — Capybara, FactoryBot, VCR.

• 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.

• Deeply nested contexts with let and before hooks become very hard to follow.
• The DSL is a language of its own to learn.
• Rails suites tend towards slowness; expect to invest in parallelisation.

• 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.

Ruby and Rails applications.

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