1. Connect
Bring your own Google Chrome UX Report API key. It's used only in your browser to call Google's public API directly — nothing is sent anywhere else, and it is never stored.
Don't have one? Enable the "Chrome UX Report API" in a Google Cloud project, then create an API key under Credentials — see Google's CrUX API documentation for the full walkthrough.
2. Choose sites
One per line: Display Name, domain.com. Paste a full URL and only the domain is used — this compares whole-origin traffic, not individual pages. Up to 20 domains per run.