website/docs/devtools/Dashboard.md
Live mode opens the DevTools UI in an external browser window and streams your test run in real time. It's the interactive counterpart to Trace Mode, which skips the UI and writes a portable offline artifact instead. Live mode is enabled by default (mode: 'live'), so simply running your WebdriverIO tests launches the dashboard.
When you run your tests, the DevTools UI automatically opens in an external browser window and tests begin executing immediately with real-time visualization. After the initial run completes, use the play buttons to rerun individual tests or suites, and the stop button to terminate running tests at any time.
The port, hostname, and devtoolsCapabilities options control the DevTools UI server and the window it opens in. See the Configuration Reference for details.