Non-standard: This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
The console.profile() starts recording a performance profile (for example, the Firefox performance tool).
You can optionally supply an argument to name the profile and this then enables you to stop only that profile if multiple profiles being recorded. See console.profileEnd() to see how this argument is interpreted.
To stop recording call console.profileEnd().
Note: This feature is available in Web Workers