There’s ONLY 2 ways to Measure Mobile Performance


Believe it or not there’s only two ways to measure Mobile Performance. And the choices are:

  1. The Wire Only – Look at what is ‘on the wire’ and then start scratching your head about why it doesn’t seem to match what you can even see with your own eyes watching the page get displayed.
  2. What is WebKit actually doing? – Look at what ‘WebKit’ is actually doing and then start scratching your head about why that doesn’t seem to match what is happening ‘on the wire’.

Either way there’s going to be some head scratching going on. Mobile is different, there’s no silver bullet and you have to carefully define exactly how you’re measuring the content.

If you’re measuring “On the Wire” then the numbers tell you how long it takes the content to get to the device. (Doesn’t tell you a thing about how it processed the content)

If you’re measuring “What is Webkit actually doing” (the User Experience) then you’re going to see what happens “after” the data has been processed. So what’s doing the processing? Well HTTP Connect is doing some (post data arriving operations) and then Webkit is doing the rest.

Welcome to Mobile – it’s NOT the same as the desktop world. Don’t believe me? Here’s some light reading…

  • Android HttpClient can hang on transfer encoding – link
  • The WebKit ‘onLoadResource’ event is called even before the resource  “starts loading” – link
  • Webkit – Provisional vs. Committed load – link and link
  • How Webkit loads a page – link


Posted in: #mobile, #webperf, #wpo, Context, Performance, Uncategorized, User Experience, WCO

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