Performance

performance.memory.jsHeapSizeLimitnumber

The maximum size of the heap, in bytes, that is available to the Javascript VM.

performance.memory.totalJSHeapSizenumber

The total heap size, in bytes, allocated by the Javascript VM.

performance.memory.usedJSHeapSizenumber

The currently active segment of the Javascript VM heap, in bytes.

performance.now()() => number

Returns the number of milliseconds since the current process started.

The resolution of the timer is platform dependent. It is usually on the order of a few micro- or nanoseconds. It uses the highest-resolution monotonic time source on each supported platform.