Chrome DevTools MCP vs Selenium

Chrome DevTools MCP

Performance traces, network inspection, heap snapshots and Lighthouse audits in one server. Usage statistics go to Google by default until you pass --no-usage-statistics.

Selenium

Selenium is stable, Apache-2.0 software on 4.51.0 with bindings in five languages, CI passing on trunk, an llms.txt and an agent guide added in September 2026. It has no MCP server of its own, Selenium Manager sends usage statistics by default, and Grid accepts unauthenticated sessions unless a username and password are set.

Chrome DevTools MCP

1. Pass pageId on every page tool. Call list_pages first to get it
2. Start with --slim for plain browsing, or turn off categories you don't need
3. Run with --isolated for untrusted sites. The default profile persists between runs
4. Use filePath on large outputs such as traces and snapshots to keep them out of context
5. Add --no-usage-statistics if the operator hasn't agreed to Google telemetry

Selenium

1. Install with pip install selenium (Python 3.10 or later) and let Selenium Manager fetch drivers. Do not set driver paths
2. Use WebDriverWait with expected conditions, never fixed sleeps, and do not mix implicit and explicit waits
3. Set SE_AVOID_STATS=true to stop Selenium Manager sending usage statistics
4. Point coding agents at https://www.selenium.dev/llms.txt. Most Selenium 2 and 3 era examples use removed APIs
5. Set --username and --password before exposing a Grid beyond localhost. Check http://localhost:4444/status before creating sessions