browser-testing

# Browser Testing with DevTools ## Overview Use Chrome DevTools MCP to give your agent eyes into the browser. The agent can see what the user sees, inspect the DOM, read console logs, analyze network requests, and capture performance data. Verify runtime behavior instead of guessing. ## When to Use - Building or modifying anything that renders in a browser - Debugging UI issues (layout, styling, interaction) - Diagnosing console errors or warnings - Analyzing network requests and API responses - Profiling performance (Core Web Vitals, paint timing, layout shifts) - Verifying that a fix actually works in the browser - Automated UI testing through the agent **When NOT to use:** Backend-only changes, CLI tools, or code that doesn't run in a browser. ## Setting Up Chrome DevTools MCP ### Installation Add the following to your project's `.mcp.json` or Claude Code settings: ```json { "mcpServers": { "chrome-devtools": { "command": "npx", "args": ["-y", "chrome-devtools-mcp@latest", "--isolated"] } } } ``` `-y` skips the npx install confirmation. By default the server launches Chrome with its own dedicated profile (under `~/.cache/chrome-devtools-mcp/`), separate from your personal browser; `--isolated` goes one step further and uses a temporary profile that is wiped when the browser closes. This is the right setup for most testing. There is also `--autoConnect` (Chrome 144+, requires enabling remote debugging via `chrome://inspect/#remote-debuggin...