Headless Browser
// Definition
A real browser running without a visible UI. Used in CI for speed and reproducibility — same rendering engine as a normal browser, with no display required.
// Code Example
# Cypress — headless run (default in CI)
npx cypress run
# Cypress — specific browser, headed for debugging
npx cypress run --browser firefox --headed
# Playwright — explicit headless flag
npx playwright test --headed=false// Related terms
Cross-Browser Testing
Verifying a web application works correctly across different browsers (Chromium, Firefox, WebKit) and versions. Modern frameworks like Playwright cover all three rendering engines from one suite.
Parallel Testing
Running multiple tests concurrently to reduce wall-clock time. Requires test independence — shared state will cause non-deterministic failures.
Auto-waiting
A framework feature that pauses an action until the target element is actionable (visible, enabled, stable). Eliminates most need for explicit sleeps and reduces flake.
Learn more · Playwright with TypeScript
Chapter 1 · Lesson 1: What Is Playwright and How It Differs from Cypress and Selenium