As a performance officer, I recently watch by a presentation from Lara Callender Swanson about how Etsy moved towards a culture of performance and mobile web by educating, incentivizing and empowering everyone who works at Etsy.
It’s important to understand that Navigation Timing data is very similar to network stats in developer tools.
Can I use … ?
Navigation Timing API is now supported by all major browsers (Can I use …?). Google Analytics and RUM services use it since a long time ago. In case, it’s not supported by your browser an error message will be displayed.
No message => don’t hesitate to create an issue on github
Mobile ready ?
This is maybe the most interesting part. Developer tools are not available on mobile/tablet version so you don’t have any chance to evaluate page load time and to explain why it may be slow.
On production ?
Here is an example on my stackoverflow profile
To conclude, don’t forget that Performance is a feature ! Displaying page load time on each page and to everyone is a great chance to detect performance issues early. Does a page violate your SLA? I think it’s now a little easier with this script.