15.8Interview Talking Point

"WebDriver BiDi is the W3C successor to both classic WebDriver and CDP. It uses WebSocket for bidirectional JSON messaging — the client can send commands AND the browser can push events. The protocol is organized into modules: session, browsing context, script, input, network, and log. And it's the present, not the future: as of 2026 it covers about 70% of the CDP surface across Chrome and Firefox, WebdriverIO v9 uses it by default, and Selenium 4 exposes it at the low level with high-level APIs slated for Selenium 5. The key advantage over CDP is standardization — a W3C spec with buy-in from all major browser vendors, not a Google-internal protocol that can change without notice."