Receiving JSON Result URL from API but no data

I have a Private Instance of WebPageTest running on Windows 7 64-bit. Everything seems to work fine with no issues.

However, when I test certain URLs, the JSON Result is not being returned. I get the JSON Result URL from the API Response, but when I go to the URL there is no data.

Here are two URLs I tested:


However, when I test this out on API, I get the JSON Result.

This doesn’t happen for all URLs, just a select few and I don’t know what is happening.

Here is my API format: http://<my_ip_address>/runtest.php?

Is there something I am not doing right, or a setting I need to make to sort this out?

P.S. I also noticed that the test ids are in a different format on my private instance (150228_CK_4) than on (150228_09_QDV). Any way I can change this to the latter?

Also, a test for doesn’t seem to work anywhere i.e. either on private instance or

If you check the box for preserve original user agent string in the advanced tab (it removes PTST from UA) then Lockheed Martin works -

As for the first issue, in the JSON response there’s a userurl link, when the JSON URLs fail I check this as it often contains some more information on what went wrong.

I’ve got some notes on this somewhere so I’ll see if I can find them a bit later

Hi Andy,

Thanks a lot for the response.

Regarding the ‘preserve original user agent string’ [for], is there a parameter for this when using the API (i.e. that I can set in my existing Webpagetest URL). I’m testing lots of sites so I can’t enter this manually.

I’ll wait for your notes on the other issue, I’d very much like to know why it’s failing.


Pretty sure it’s keepua=1 to use the browser’s default User Agent string.