Deno supports User Timing Level 3 which is not widely supported yet in other runtimes.

Encapsulates a single performance metric that is part of the performance timeline. A performance entry can be directly created by making a performance mark or measure (for example by calling the .mark() method) at an explicit point in an application.

PerformanceMark is an abstract interface for PerformanceEntry objects with an entryType of "mark". Entries of this type are created by calling performance.mark() to add a named DOMHighResTimeStamp (the mark) to the performance timeline.

Options which are used in conjunction with performance.mark. Check out the MDN performance.mark() documentation for more details.

PerformanceMeasure is an abstract interface for PerformanceEntry objects with an entryType of "measure". Entries of this type are created by calling performance.measure() to add a named DOMHighResTimeStamp (the measure) between two marks to the performance timeline.

Options which are used in conjunction with performance.measure. Check out the MDN performance.mark() documentation for more details.