Missed the action at the 2018 Chrome Dev Summit? Catch up with our playlist on the Google Chrome Developers channel on YouTube. Watch now.

Time to Interactive


Load is not a single moment in time — it’s an experience that no one metric can fully capture. There are multiple moments during the load experience that can affect whether a user perceives it as "fast" or "slow".

--- Paint Timing spec

The Time to Interactive (TTI) metric measures how long it takes a page to become interactive. "Interactive" is defined as the point where:

  • The page has displayed useful content, which is measured with First Contentful Paint.
  • Event handlers are registered for most visible page elements.
  • The page responds to user interactions within 50 milliseconds.

Some sites optimize content visibility at the expense of interactivity. This can create a frustrating user experience. The site appears to be ready, but when the user tries to interact with it, nothing happens.


To improve your TTI score, defer or remove unnecessary JavaScript work that occurs during page load. See Optimize JavaScript Bootup and Reduce JavaScript Payloads with Tree Shaking, and Reduce JavaScript Payloads with Code Splitting.

Tracking TTI in the real world

To measure when TTI actually occurs on your users' devices, see Tracking TTI. The code snippet describes how to programmatically access TTI data and submit it to Google Analytics.

TTI can be difficult to track in the wild. You may prefer to track First Input Delay, instead.

More information

See Definition for more details on how exactly TTI is calculated.

This metric was previously called Consistently Interactive.



Was this page helpful?