Seeking Info on User timing and Page is Interactive

Appears there are some new features - I didn’t see an announcement or perhaps overlooked it. Would appreciate info on these:

User timing - This is located next to the Start Render or Speed Index as a number in seconds e.g. 6.795s.

Page Is Interactive - This is located below the Browser Main Thread and appears on mobile runs.

Would like to know the following:

  1. how it’s calculated - I assume it has to so with something with Javascript blocking
  2. Is the data available? I would like to get the total seconds when the page is interactive, versus not interactive. (I wasn’t able to find it in XML)
  3. how its defined - I assume this is when the user can scroll but is unable to click on the page. Any info would be appreciated.

I figured out the User timing question - I had inserted a W3C User Timing mark onto the page I was testing and realized it outputs that user timing. - see http://www.webperformance.io/custom-user-timings.

Page interactiveness is defined here: webpagetest/TimeToInteractive.md at d137df7a233a2ee941c24334542ddc17248a6e54 · WPO-Foundation/webpagetest · GitHub

Interactive Window

The browser’s main thread is considered “interactive” when it is not blocked for more than 50ms by any single task so it will be able to respond to user input within 50ms. An interactive window is a period of at least 5 seconds where there are no main-thread tasks that take more than 50ms.