To measure CDN performance impact:
- Use Query Monitor for detailed performance analysis
- Monitor page load times using tools like GTmetrix or PageSpeed Insights
- Track CDN bandwidth usage and cache hit rates
- Compare before and after performance metrics
Key metrics to monitor: Time to First Byte (TTFB), page load time, server response time, and CDN cache hit ratio. Regular monitoring helps identify optimization opportunities and potential issues. Consider implementing real user monitoring (RUM) for accurate performance data across different geographical locations.

