Cypress

Cypress is a JavaScript testing tool for anything that runs in a browser. It runs end-to-end and component tests directly in a real browser and shows them executing in real time, driving the application the way a user does, so that a passing run means the flow actually works.

Failures can be rewound step by step to see the state of the application at each command. Recent versions add cy.prompt, which turns plain-language test descriptions into self-healing steps that adapt when a button moves or is renamed, and Studio AI, which records clicks through the application and generates runnable Cypress tests. Coding agents can drive the same browser session.

The Cypress app is open source under the MIT licence and actively maintained on GitHub. Cypress Cloud, a commercial service, adds test replay, parallelisation, and coverage and accessibility results on every run, locally, in CI or from a coding agent.