Last Updated: 13 Apr 2021 05:41 by ADMIN

MacOs, Fiddler Everywhere 10, Cisco AnyConnect.

Here's the workflow...

In the morning, Cisco VPN isn't connected.  All traffic is blocked by design.  Attempt to start Fiddler Everywhere.  WON'T START because it can't login.  What is this new requirement to login?  If I don't start Fiddler before the VPN, no traffic ever logs.  If i don't start the VPN, Fiddler won't start.  A bit of a cartch-22, ya think?

Somehow I bypass the VPN (Don't tell corp security) and get logged-in.  Fiddler is up.  Start the VPN. Get some work done.  Shiny new UI!  Still can't drag-drop from inspector to composer?  Damn.

At some point the Fiddler login EXPIRES.  Why does it expire?  What do I even need a login for?  At this point ALL TRAFFIC fails, since Fiddler was the system proxy.  All work stops.  Now I need to stop Fiddler, Stop the VPN, attempt to start Fiddler again....oh wait, can't login because the VPN is down...  here we go again.

This is all a serious waste of time.  I can see registering Fiddler so you know who your users are.  What's with the REQUIREMENT to have a login, and why does it expire?  It kinda makes Fiddler useless.

Please remove the requirement to login to an account before being able to use Fiddler Everywhere.




Last Updated: 02 Mar 2021 14:38 by ADMIN


When I try to trusst the fiddler root certifficate, I get the message "not successfull" and see a line like this in the logfile:

[2021-03-01 16:29:48:866] [Information] [Fiddler] Error when trying to check if certificate is trusted: '.', hexadecimal value 0x00, is an invalid character. Line 304, position 38.

I also tried to trust the certificate by hand via the keyring utility.

What can I try?



Last Updated: 05 Nov 2020 15:19 by ADMIN

I'm unable to connect to "gateway.icloud.com" when Fiddler is open and decrypting HTTPS traffic.

This is Fiddler Everywhere 0.10.0 on macOS 10.15.5.

To reproduce:

Open Fiddler and make sure it's decrypting HTTPS traffic.

Open any browser and go to https://gateway.icloud.com/

Expected result: Page loads (it's blank. This is normal.)

What actually happens: fiddler.network.https> HTTPS handshake to gateway.icloud.com (for #820) failed. System.Security.Authentication.AuthenticationException The remote certificate is invalid according to the validation procedure.


Same thing happens on https://configuration.apple.com/

Last Updated: 16 Sep 2020 13:44 by ADMIN

Steps to reproduce:

  1. Post a 69k request to a web api (encoded JSON data) via browser.
  2. Inspect request data in Text and Raw fields.
  3. Observe that the data is truncated in the middle of a property name (not a null char).

Example data posted (snippet with middle section excerpted):


There is much more data that should occur after the property "immediatePatientSafety".  There does appear to possibly be additional fields presented in the Web Form inspector although some of the values are truncated and have an ellipsis (...) following those lines, so I believe that the tool is capturing the data but will not make it visible or available in the Text or Raw Inspectors.

No option exists to configure the amount of request data that is captured or to cause the Inspector to "show more" data.

I need to be able to see the full text request to troubleshoot an issue with the back-end application.

I need the data available in the Text or Raw inspector so that I can cut and paste it out for external processing and discussion with the developers.

I noted that a separate bug report has been issued for a missing "show more data" option on large response records.




Last Updated: 14 Aug 2020 09:21 by ADMIN

Latest version of Fiddler (v0.10.0) and Android Emulator is not proxying the connections properly.

I have Fiddler Everywhere running and know it is working when I can send requests through Postman and see them show up in Fiddler properly.

However, if I set up the Android Emulator through Android Studio, and set the proxy to be Fiddler, connections do not fully reach the backend service I am sending requests to. All that shows up in Fiddler is




HTTP/1.1 200 Connection Established
FiddlerGateway: Direct
StartTime: 16:12:05.141
Connection: close

The service is running on my local host machine ( on port 5000.

If I close Fiddler and run charles-proxy, then set the Android Emulator to use that as the proxy, I see the full request, my service responds, and I see the response in Charles.

Last Updated: 03 Aug 2020 13:20 by ADMIN
Scheduled for FiddlerCore Release

Hi there,

I've successfully setup fiddler-everywhere 0.4.0 and am able to sniff traffic to various websites on my linux (Ubuntu 18.04) laptop. However some https sites are not working - fiddler-everywhere severs the connection at the SSL handshake phase. These same sites work in the windows version of Fiddler (v 5.0.20192.25091 - built 04 June 2019) however.

What is the status of the SSL support in fiddler-everywhere vs windows Fiddler?

Example site that fails over https:

Example site that works over https:

Fiddler captures for absa.co.za


CONNECT www.absa.co.za:443 HTTP/1.1
Host: www.absa.co.za:443
Connection: keep-alive
User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/75.0.3770.142 Safari/537.36

A SSLv3-compatible ClientHello handshake was found. Fiddler extracted the parameters below.

Version: 3.3 (TLS/1.2)
Random: 1F 0E B0 54 5D 66 42 82 C9 A8 A6 D5 8F C2 F0 C6 A8 16 0C 8E 14 45 F2 B4 B5 95 92 66 B6 53 D6 F4
"Time": 2015/01/09 19:21:35
SessionID: empty
	0x5a5a		empty
	server_name	www.absa.co.za
	extended_master_secret	empty
	renegotiation_info	00
	elliptic_curves	unknown [0xBABA), unknown [0x1D), secp256r1 [0x17], secp384r1 [0x18]
	ec_point_formats	uncompressed [0x0]
	SessionTicket	empty
	ALPN		h2, http/1.1
	status_request	OCSP - Implicit Responder
	signature_algs	sha256_ecdsa, Unknown[0x8]_Unknown[0x4], sha256_rsa, sha384_ecdsa, Unknown[0x8]_Unknown[0x5], sha384_rsa, Unknown[0x8]_Unknown[0x6], sha512_rsa, sha1_rsa
	SignedCertTimestamp (RFC6962)	empty
	0x001b		02 00 02
	0xeaea		00
	[5A5A]	Unrecognized cipher - See http://www.iana.org/assignments/tls-parameters/
	[002F]	TLS_RSA_AES_128_SHA
	[0035]	TLS_RSA_AES_256_SHA




HTTP/1.1 200 Connection Established
FiddlerGateway: Direct
StartTime: 10:28:40.706
Connection: close

fiddler.network.https> HTTPS handshake to www.absa.co.za (for #329) failed. System.IO.IOException Unable to read data from the transport connection: Connection reset by peer. < Connection reset by peer

Last Updated: 01 Jul 2020 09:05 by ADMIN

On Request Inspector Screen, Web Forms Tab, I'm unable to highlight or copy contents. Cmd + A also doesn't work to highlight contents. 
Last Updated: 01 Jul 2020 08:20 by ADMIN

On Request Inspector, Web Forms Tab, the header row seems duplicate. 

Last Updated: 01 Jul 2020 07:08 by ADMIN

While inspecting requests where Content-Length > 3000, only 3000 characters of the request body gets displayed in both Raw and Text views. When I copy the whole contents of the selectable area (CMD + A, CMD + C) and paste it into a text editor, it seems like there is a 'View full request...' text somewhere which does not show up. I remember this button from previous versions. 

OS : macOS Mojave Version 10.14.6

A sample HTML with dummy form to reproduce the bug and recorded session is attached. 

Last Updated: 02 Jun 2020 06:26 by ADMIN
Created by: Ryan
Comments: 9
Type: Bug Report

I fire up Fiddler Everywhere on my Mac. Generally, it appears to do nothing.

In further detail, "Stream" and "Decode" can be toggled, but otherwise do nothing. The connections icon has a hover-over describing my host and states I have a network connection. The help icon goes to the very limited documentation via browser. The settings icon pops open the settings dialog, which does appear to save changes, but not impact the "nothing" being done by the application. The capture button and inspectors button appear to do nothing. The main viewing area states "No records available." The area to the right of the main area states "Please, select a single Web Session to inspect." And that is it.

Either I'm doing (or not doing) something dumb, or it just isn't working for me. Any help would be appreciated :)

Mac specs: High Sierra 10.13.6, 2.6GHz i7, 16 GB memory

Last Updated: 01 Jun 2020 14:31 by ADMIN
Created by: Leonardo
Comments: 1
Type: Bug Report

Simple as that: fiddler everywhere does not capture traffic to localhost, AND when you insert your local address, it captures your request only to return that "

[Fiddler] DNS Lookup for "www." failed. System.Net.Internals.SocketExceptionFactory+ExtendedSocketException Device not configured



MAC OSX, using safari.

Other address are captured as expected

Last Updated: 06 Feb 2020 21:19 by Robert Colbert

Describe the bug
When the location of the Windows Desktop is changed (e.g. like described here), the functionality for exporting the root certificate is not working.

To Reproduce
Steps to reproduce the behavior:

  1. Change the location of the Desktop on Windows OS
  2. Run Fidder Everywhere, ensure that Setting -> HTTPS -> Decrypt HTTPS traffic is checked
  3. Press Settings -> HTTPS -> Decrypt HTTPS traffic -> Export root certificate to Desktop
  4. Error message is shown in a tooltip:

Could not find a part of the path 'C:\Users<username>\Desktop\FiddlerRootCertificate.crt'.

Expected behavior
The certificate is exported.

Desktop (please complete the following information):

  • OS: Windows 10
Last Updated: 20 Jan 2020 07:19 by ADMIN
I installed Fiddler Everywhere on Fedora 31. Clicking "View full response" for any response opens a pop-up window which is reasonably sized, but the content of which is a scrollable area about one line high at the top of the window and there is no obvious way to expand it to see more than one line of the response. Screenshot attached.
Last Updated: 16 Oct 2019 13:36 by ADMIN
Created by: Carsten
Comments: 1
Type: Bug Report

Fiddler can't connect to domains with 3 consecutive hyphens.

This error occurs:

fiddler.network.https> HTTPS handshake to r1---sn-ab5szn7e.googlevideo.com (for #793) failed. System.ArgumentException Decoded string is not a valid IDN name.
Parameter name: unicode


To reproduce:

Start Fiddler Everywhere (at least on Mac), make sure HTTPS decryption is enabled.

Go to www.youtube.com and try to watch a video.

The aforementioned error will occur in Fiddler.