Just wanted to point out you need to run the 32-bit version of mono to get this to launch without errors.  The maintainers should probably point out that on the Mac download page.

To run it, you need to do a:

'mono --arch=32 Fiddler.exe'

Dear all expert users,

I work with a web app having a specific issue working with Edge browsers. To inspect what happens, I wanted to monitor and debug with Fiddler, but I just can't make my Edge browser communicate with Fiddler2. My environment looks like this:

* Microsoft Edge 38.14393.0.0; proxy settings: Automatic
* Windows 10
* Fiddler v4.6.3.44034
* disabled Windows Firewall.

(1) Browsing in Edge with Fiddler off:
I can surf about as desired.

When I now inspect Edge proxy settings, they are set not to use a proxy. This is as expected.

(2) Starting Fiddler and trying again:

Any attempts to load a web page makes Edge complain, it can not connect to the proxy server (Fiddler). 

This time, Edge proxy settings were changed after Edge restart. Now it's set to use 127.0.0.1:8888 for HTTP and HTTPS, as expected. 

If I try opening another browser session from Fiddler, IE works well and Chrome works well. Only Edge does not connect to the proxy..

I read other threads on this forum, and found suggestions this might happen because of windows firewall, possibly even some hard coded matter in the firewall. However, as I stated above: My problem persist even with firewall turned on or off. Therefore my conclusion: Edge and Fiddler don't cooperate, and it has not to do with the firewall settings.

Uless of course, anyone is able to explain to me what happens or how to make things work. (It would typically be some simple setting I have got wrong, for sure.. You'd make me really happy, if you made me understand. :-)

Cheers,

Aril

I have 2 pc in my home and 1 mac

All 3 are connected to the same router.

The mac has wifi hotspot, so I connect iphone with mac wifi.

When I connect iphone with fiddler on mac (virtual machine win 10) it works fine.

But when I connect iphone with fiddler on a windows pc. It doesnt work at all.

This used to work for me when I had another modem. 

So router:
pc1
mac


Iphone wifi mac ->fiddler mac (virtualbox ok)

iphone wifi mac -> fiddler pc  ( not ok )

This used to work for me, but I dont know why It doesnt work anymore, Im sure it has to do with the router/modem
Before was a motorola now its a shitty thompson

Having an issue maybe I just need some ideas how to check.. have this mobile app that gets pushed a notification somehow to pull requests from a service (api), I have configured a fiddler proxy as the only means for the device having the app to reach the internet.  When a notification comes so the app can reach for info I don't see any evidence of this on fiddler session logs, is there any way of seeing this somewhere without having to use more tools like wireshark? reason is https decryption seems little more complex there.  Next issue is once the app reaches for info and send the request (the app does the request multiple times over a period of time to get the most updated info while waiting for user's action), and I'm tampering the response making sure I use "oSession.bBufferResponse = true;" in the "OnPeekAtResponseHeaders" for that method so response is not streamed to the client first then changing the response in the "OnBeforeResponse" method but it seems by visual observations the modified response doesn't get passed to the client until the 2nd or 3rd request, sometime you can observe the response displayed in the client is the unmodified one even though in the logs I can see I successfully tampered all the responses for all the requests.  I'm looking for ideas on how to realize if I'm doing something wrong.

Thanks for whoever can give me a hand.

I would like to connect to a HTTP Proxy with Fiddler Core.

I'm using the 

code to do it.

Now authentication is needed for the proxy. I see in other question a solution. It says:

Where the hash at the end is the Base64 coding of the 'username:password'

My question about this workaround:

 
It results a HTTP_PROXY_AUTHORIZATION HTTP header to my requests. Not just from fiddler to the proxy, but also from the proxy to the web.
Shouldn't it be removed by the proxy? As it says here? https://tools.ietf.org/html/rfc7235#section-4.4
Is there a workaround with FiddlerCore so I can connect a HTTP Proxy with credentials without HTTP headers?

NOTE:

When I use Proxifier to connect the same proxy it works without the headers being visible by the websites

Hi,

is it possible to change the location of listeningProcess.txt?

I think it would be good to locate that file in the users home folder or in /tmp.

If this file is stored with the exe file, it is not possible to install fiddler in /bin and run without root privileges.

Kind Regards

Benjamin

Hi there,

can you help me? I want to search and replace ainside a html-file.

It means there is a request like "index.html" and than I want to replace a part of this with a local snippet and at the end it should be delivered to the brower as "the respond"

At the Moment I write a Funktion and call it

*script:TestFunc

It is called because I see a log, but I do'n't know what's next :-/

Thanks!

Cya

Dominic

Hello, 

I am attempting to capture traffic to troubleshoot an ongoing issue, however I cannot get FiddlerCap to work with the Edge browser.  When I start a capture I get the message "Can't connect to proxy server."  This only happens while Fiddler is running.  If I stop the capture, I have no issues getting to the internet.  I'll attach some files to show my settings.  Thank you so much for your guidance!

-Kerry

I'm working on bunch of projects, all on .net Core 2.0 / Standard 2.0, that require making Web Services calls. WS calls are made through proxy generated from a Connected Service reference. I've been working on these projects for an year+ and have been using Fiddler regularly. I'm on Windows 10, VS 2017, latest version of Fiddler 5.0.20181.14850.

I don't know exactly what changed recently (there were OS updates, VS updates, etc). But, WS traffic is no longer captured in Fiddler. Anything else to HTTP/HTTPs endpoints are captured. Even if I make a call to the WS endpoints with just a HTTP WebClient class, from code, it shows up in Fiddler. This is true to .NET Core Web API projects, Console app projects and XUnit Test classes.

I might be able to resolve this by pointing the code to the Fiddler proxy. But, given that this has worked for so long, I want to understand what happened and possible resolve it without going the proxy path.

Any ideas would be appreciated.

Thanks

I have a console app that communicates with a number of 3rd party services via http. The original version of the app is developed for the .net Framework and Fiddler is able to successfully all of the https calls that the app makes.

I have ported the app to .Net Core 2.1. Fiddler is not capturing the HTTPS calls made by the .Net Core version of the app.

Any ideas as to why Fiddler is not working with the .Net Core app?