First Steps with Fiddler Everywhere on macOS

This tutorial describes how to install and start using Fiddler Everywhere on macOS.

  • First, you will go through the installation and configuration steps.
  • Next, you'll create a Fiddler account so that you can move on to effectively using the web-debugging tool.
  • Then, you will switch the default Light theme with the Dark one.
  • Finally, you will see how to capture, inspect, and modify traffic.


  • Install macOS High Sierra (10.13+) x64.
  • Provide 300MB of free disk space.
  • Create an account with administrative rights which you'll need for capturing and decoding HTTPS traffic.
  • Provide an active internet connection with access to the following URLs:

Installing Fiddler Everywhere on Your Machine

You'll first have to install the latest version of Fiddler Everywhere on your machine.

  1. Navigate to the Fiddler Everywhere download page.

  2. Select Download for OS X to download the installer.

  3. Run the Fiddler Everywhere dmg file to start the installation process.

Creating Your Fiddler Account

In this step you'll register by creating your personal Fiddler Everywhere account and become a trial user.

  1. Launch the Fiddler Everywhere client. Select the New User? Sign up button.

  2. On the Create Account screen, enter the requested information and accept the terms of the agreement. The email you provide here will be later on used by your collaborators for sharing sessions, collections, and notifications.

  3. Open the confirmation email and verify your Fiddler registration by entering the unique code.

  4. Fill in the required information and proceed through the Let's Go button.

  5. On the next screen, choose whether you want to become a trial user or purchase a subscription plan by selecting either the Start Free Trial or the BUY NOW link. For the purposes of this tutorial, you'll become a trial user by selecting the Start Free Trial option. You are all set to start using the full-scale functionalities Fiddler Everywhere delivers.

Trusting the Root Certificate

Now you can track non-secure HTTP traffic with Fiddler Everywhere. To be able to handle HTTPS traffic, however, you'll have to install a trust certificate.

  1. Start Fiddler Everywhere and go to Settings > HTTPS. Click the Trust Root Certificate button.

  2. In the window that appears, enter your machine administrative credentials.

    Enter Keychain credentials to trust the root certificate

  3. Enable the capturing of the HTTPS traffic by selecting the Capture HTTPS traffic checkbox and clicking Save.

Styling the Tool

Now let's add more elegance to Fiddler Everywhere and change its default Light theme with the Dark one—just go to the Themes menu, select the Dark theme, and click Save. That's it!

Fiddling with the Traffic

Let's now continue with capturing and inspecting some HTTPS traffic:

  1. Inspect each session's request and response data through the Inspectors tab.

  2. Extract more details and statistical data by using the Overview tab.

Now you'll extract a captured session:

  1. Go to the Live Traffic tab and select a request/response entry from under the sessions list.

  2. Double-click to open the Inspectors tab and inspect the detailed session request/response data.

  3. Switch to the Overview tab to observe technical and statistical data.

Let's modify that session!

  1. Right-click the session of your request to open the context menu of the entry. From there, select Edit in Composer.

  2. When the session opens in a new Composer window, modify its headers. For example, add new HTTP header with the isTest key and the true value.

  3. Click the tick to add the new HTTP header.

  4. Click the Execute button to replay the modified request.

That was it! Now you are ready to dive more deeply into Fiddler Everywhere and take full advantage of its slick functionalities!

Next Steps

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