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

What worked for me is to reset the fiddler https certificate and recreate it.

Fiddler version V4.6XXX 

Fiddler menu-> Tools-> Telerick Fiddler Options... 
Second tab- HTTPS-> Action -> Reset All Certificate

Once you do that, again check the check box(Decrypt HTTPS certificate)

Answer 2

I had the same issue with Firefox. The solution was to set the proxy settings to "system proxy settings". Fiddler can only capture traffic that goes through its proxy server. Capturing was stopped because a few days ago I was tinkering with the Firefox proxy settings for another project.

It follows that using Chrome you should also check the browser proxy settings in case of problems with capturing traffic with Fiddler.

Read more about this on the Fiddler site

Answer 3

I've had the same problem. The solution was to remove proxy from Chrome settings. Also you could have an extension that use proxy. Try to disable it.

Answer 4

Make sure you have Capture Traffic enabled by making sure it's checked under File.

It's sadly too easy to press F12 by mistake with Fiddler focused and disable the whole thing.

Answer 5

Same problem here, in all browsers (IE, Chrome, FF). Upon startup the Fiddler Log tab showed the following:

"!WARNING Fiddler has detected that system or domain Group Policy has set ProxySettingsPerUser to 0. Unless Fiddler is run Elevated (e.g. Run As Administrator), it may not capture traffic from Internet Explorer and other programs. Current process IS running Elevated."

I'm in a huge corporate environment, with no connection to or info about group policy changes; it apparently just got applied one day. Thanks, bureaucracy :)

Anyway, that led me to messing around with IE proxy settings. Changing it from Automatic to 127.0.0.1 on port 8888 (the default configured port in Fiddler) worked. Kind of a pain, though, because I have to set it each time to override the group policy setting. And then I get cert errors, which is a known thing because Fiddler uses it's own, untrusted cert . . . and the beat goes on . . .