IE 11 support stopped working?

Did IE 11 support stop working recently?

IE 10 works fine

IE 11 for the same page fails to capture most of the requests and traffic

I tried IE 11 using a private instance with the latest release with the same results. I believe I’ve seen it working correctly before but I am not totally sure.

Hmm, thanks - I’ll take a look.

I know I had a problem where IE 11 wasn’t reading responses so everything showed up as a -2 so it was on my list to look at (like this: ). I’ll take a crack at it today. Looks like they probably just evolved how they read/write to the sockets and schannel and I need to adapt the hooking.

Oh, any chance that that page is SPDY? IE 11 introduced SPDY support and the WPT agent doesn’t have a SPDY decoder yet (been on my todo list for a while).

I believe the site is not SPDY

It is strange that IE11 fails for this site but works on others.
Can the http compression play a role?

Sorry it took so long to get fixed. Both the missing requests and the failure to process responses should be fixed for IE 11 now: (was never working correctly).

Thanks Patrick !


I had the same problem with IE11 and I saw on github that you fixed the problem : Fixed issues with capturing IE 11 requests (changes to their socket u… · WPO-Foundation/webpagetest@23067ee · GitHub

But the 2.13 version was released 4 months ago and seems to not contain the fix.
Do you plan to make a new release with this fix soon ?

Hopefully next week as I clean up a few other nagging issues. That said, you can always update the agents separate from the www releases (and I recommend it):

Thanks for the update
I installed the new version and they seem to work fine, except maybe a problem with chrome but I’ll check that further.

Why the reco ?