Difference between Cypress and Playwright?

The Answer

Both are modern testing tools but differ fundamentally in architecture. Cypress runs JavaScript INSIDE the browser (same thread as the app). Playwright controls the browser from OUTSIDE via WebSocket — making it capable of multi-tab, multi-origin, and iframe testing that Cypress struggles with.

Deep Dive Explanation

Key comparison table: Cypress - JS only, Chromium/Firefox only, same-origin, in-browser, great DX, real-time reload. Playwright - JS/TS/Python/Java/C#, Chromium/Firefox/WebKit, cross-origin, out-of-process, excellent debugging tools, fastest execution.

example.spec.ts

// Playwright: Multi-origin in ONE test (impossible in Cypress without workarounds)
test('multi-origin flow', async ({ page }) => {
  await page.goto('https://app.com/login');
  await page.getByRole('button', { name: 'SSO Login' }).click();
  // Playwright follows the redirect to another domain seamlessly
  await page.waitForURL('https://sso-provider.com/auth');
  await page.getByLabel('Username').fill('user@app.com');
  await page.getByRole('button', { name: 'Sign In' }).click();
  await page.waitForURL('https://app.com/dashboard');
});