How much can performance optimization improve my website speed?

Performance optimization typically improves load times by 50-70%, with some sites seeing 80%+ improvements. Results depend on starting point—sites with major issues see bigger improvements. Typical improvements include reducing load times from 5-6 seconds to 1-2 seconds. Core Web Vitals improvements often move sites from 'needs improvement' to 'good' ratings. Factors affecting results include current performance, optimization scope, and technical constraints. Good consultants set realistic expectations based on your specific situation. Even small improvements (1-2 seconds) can significantly impact bounce rates and conversions. The key is systematic optimization addressing all bottlenecks.