Start Offset Time - Insanely Huge on Chrome (First View)

Web Performance Discuss Test Results
1

Hi,

I’ve started getting these very strange results. This is happening just occasionally, only on Chrome (all the other browsers are fine), from almost all locations, and only on the first view, but very rarely from Dulles, VA.

What happens is that on the first view in Chrome the Start Offset time is ridiculously big (thus the Speed Index too). Essentially nothing happens for 1406037.122 seconds and then the website starts to respond.

http://www.webpagetest.org/result/131122_Z0_BP/

Webpagetest manages to produce full screenshot of the website although the very first signal starts to show up after many minutes… according to the stats.

This is illogical because Webpagetest loads the page in several seconds (the test lasts for several seconds), produces the screenshot (not able to produce the video), but reports that the website needs thousands of seconds to responds due to the very big Start Offset time. If that is the case why the test is not lasting for several minutes.

As I’ve said this is only happening on Chrome, the first view, from most of the locations but not all.

Any thoughts?

2

Something must be screwed up with the timings coming from Chrome’s dev tools and it isn’t getting filtered out. I’ll take a look when I get back to the office in a week or so.

3

I opened an issue to track it: Chrome dev tools timings are sometimes way off · Issue #156 · WPO-Foundation/webpagetest · GitHub If you follow it you’ll get notified when I get it fixed.

4

Okay thanks @pmeenan. So it’s Chrome right? I was wondering why this issue isn’t happening on other websites I’ve tested?

5

Yep, Chrome and probably SSL specific.

6

Should be fixed now - let me know if you see it again.