Fiddler not capturing traffic from browsers

Question

I\'ve been using Fiddler for quite a while, but all of a sudden it no longer captures internet traffic. I\'m on Chrome 29 and Fiddler v4.4.5.1. I\'ve checked all filters a

Answer 1

I had the same problem, but it turned out to be a chrome extension called hola (or Proxy SwitchySharp), that messed with the proxy settings. Removing Hola fixed the problem

Answer 2

As Thomas Glick said, the latests versions of Fiddler2 works ok with all major browsers. But beware, there's a "Show only Internet Explorer traffic filter" in the filters sections, just disable that one and everything should work as expected, including other filters.

Answer 3

I know this answer is really late, and probably not relevant to what the submitter had 3 years ago, but I found another possible reason why people may not get Fiddler to work, specifically in an Enterprise environment.

We are in the middle of releasing Fiddler. For my company, we are not allowed to download apps and install ourselves. We have to request IT to approve it and install it via ordering it from a software "Store" here at the company.

To get Fiddler to be available to "order" from that "store", we have to test on test machines. During testing, we could not get Fiddler to update the IE11 proxy settings. When I installed Fiddler myself, it would work, but when I had IT install it using the authorized install channels (what we were testing for), it would not work. Even when we try with users with Local Admin rights, and Run As Administrator, no luck.

At first we thought it was a Group Policy thing, but looking into it, it wasn't the case.

It turns out the IT people wrapped Fiddler in a VMWare ThinApp wrapper, an invisible VM sandbox to wrap the app inside of. I don't know what the benefits are of ThinApp, but it prevented Fiddler from being able to update the Proxy settings if IE11. When you enable capturing, and open WinINET options in Fiddler, it would show the Proxy settings updated. But when you opened IE11 Connection Settings, the proxy was not updated. Makes sense.

So the IT folks decided to release it as a "fat app" (that's what they called it) and now it works like a charm.

Just wanted to get this on the internet so that people are aware of it.

Answer 4

I had the same problem with a Chrome extension called GeoProxy - even though proxy was disabled, it still took the traffic away and stopped fiddler from seeing it. Disabling the extension resolved the issue. I'm guessing this will be an issue with any proxy extension.

(This was meant just as a comment for Claus' response above, which set me on the right path - but apparently I have enough reputation to answer, but not to comment...)

Answer 5

Russian, this info for you! Fiddler didn't capture Chrome traffic because I had installed Antizapret Chrome addon for access blocked by Russian government sites. I removed it and now all works.

Answer 6

I had the same issue and resolved it by running Fiddler with elevated privileges (aka, Run As Administrator)