Selenium is a language-agnostic browser-automation library driving browsers via WebDriver; Cypress is a JavaScript-only, all-in-one E2E framework running inside the browser. They differ in architecture, language support, waiting, and scope.
Selenium supports many languages (Java, Python, C#, JS) and all major browsers, runs out-of-process via WebDriver, and needs a separate test runner/assertion/reporting stack. Cypress is JS/TS only, bundles the runner, assertions, mocking, and dashboards, runs in-browser with automatic waiting, and excels at controlling app state and network. Selenium is better for broad cross-browser/language coverage, mobile (via Appium), and multi-tab/multi-window scenarios; Cypress is better for fast, reliable, developer-friendly front-end testing with network stubbing. Choosing between them depends on team language, browser matrix, and whether you need in-browser control or broad platform coverage.
A Java-heavy enterprise with a large cross-browser matrix keeps Selenium + REST Assured for backend/UI coverage, while a React startup adopts Cypress for fast, stub-driven front-end tests that developers write alongside features.
Your team needs to test a flow that opens a payment provider in a NEW browser tab. Which tool fits better and why?