The main difference is Scalene is a sampling profiler, and Memray appears to be an instrumentation profiler. Instrumentation profilers usually give more precise

The main difference is Scalene is a sampling profiler, and Memray appears to be an instrumentation profiler. Instrumentation profilers usually give more precise information at the cost of a slowdown. From Memray: > Traces every function call so it can accurately represent the call stack, unlike sampling profilers.