4.2The Three Eras of Browser Automation

Era 1: Selenium (2004–2018)

Selenium defined the space. It introduced the WebDriver protocol — a W3C standard where test code sends HTTP+JSON commands to a driver process, which commands the browser. Every interaction is an HTTP round-trip.

Test Code  --(HTTP/JSON)--> ChromeDriver --(DevTools Protocol)--> Chrome

This architecture brought cross-browser, cross-language automation to the industry. It also brought inherent latency, flaky waits, and a maintenance burden that scaled poorly.

Era 2: Direct Protocol Tools (2017–2020)

Puppeteer (2017) proved that connecting directly to Chrome's DevTools Protocol over a persistent WebSocket was dramatically faster and more reliable. Cypress (2017) took a different approach by running inside the browser itself. Both sacrificed Selenium's breadth for speed and developer experience.

Era 3: Playwright (2020–Present)

Playwright, built by the team that created Puppeteer, combined the best of all approaches: direct protocol connections to Chromium, Firefox, and WebKit, with a unified API, auto-waiting, and built-in test infrastructure. It has become the default choice for new projects.