Jest is a JavaScript testing framework that works with Babel, TypeScript, Node, React, Angular, Vue and more.

Yes. Jest is open source under the MIT licence. Its source code is on GitHub at jestjs/jest and is written mainly in TypeScript.

Yes. Jest is open source, so the software itself is free to use.

Can I self-host Jest?

Yes. Jest can be self-hosted on your own server or infrastructure.

What is Jest an alternative to?

Jest is an open-source alternative to Katalon, mabl and Parasoft. Other open-source alternatives to Katalon include Playwright, Appium and Robot Framework.

Is Jest actively maintained?

Yes. The most recent commit to Jest was on 13 October 2026, and the latest release is v30.5.2, published on 18 September 2026. The project has 46k stars on GitHub.

Jest: open-source alternative to Katalon, mabl, Parasoft

About Jest

Jest is a JavaScript testing framework designed to ensure correctness of any JavaScript codebase. It allows users to write tests with an approachable, familiar and feature-rich API that gives results quickly. Jest is well-documented, requires little configuration and can be extended to match requirements.

Key features

Zero config: works out of the box on most JavaScript projects
Snapshots: keep track of large objects alongside tests or embedded inline
Isolated: tests run in their own processes for parallel execution
Fast and safe: runs previously failed tests first and re-organizes runs based on test file duration
Code coverage: generate coverage with the --coverage flag, no additional setup needed
Easy mocking: custom resolver for imports, mock any object outside test scope

Built with: TypeScript tools; JavaScript tools
Tags: javascript; testing; unit-testing; snapshot-testing; code-coverage

Jest: questions and answers

What is Jest?: Jest is a JavaScript testing framework that works with Babel, TypeScript, Node, React, Angular, Vue and more.
Is Jest open source?: Yes. Jest is open source under the MIT licence. Its source code is on GitHub at jestjs/jest and is written mainly in TypeScript.
Is Jest free?: Yes. Jest is open source, so the software itself is free to use.
Can I self-host Jest?: Yes. Jest can be self-hosted on your own server or infrastructure.
What is Jest an alternative to?: Jest is an open-source alternative to Katalon, mabl and Parasoft. Other open-source alternatives to Katalon include Playwright, Appium and Robot Framework.
Is Jest actively maintained?: Yes. The most recent commit to Jest was on 13 October 2026, and the latest release is v30.5.2, published on 18 September 2026. The project has 46k stars on GitHub.