profile

The profile snippet enables performance monitoring by leveraging the Performance API to track execution timing. It marks key points and measures the elapsed time between them in milliseconds.

Notes

The snippet logs performance data as an object when activated.
Firefox reduces the precision of timestamps to protect user privacy, which can result in rounded values such as 0 or 1.

Firefox configuration

To obtain more precise measurements in Firefox, navigate to about:config and toggle privacy.reduceTimerPrecision to false. If rounded values persist, toggle privacy.resistFingerprinting as well.

Examples

profile; abort-on-property-read atob — activates profiling for property-read monitoring
profile; debug; abort-on-property-read atob — combines profiling with debug mode