Live Traffic Tab

The Live Traffic tab is an essential feature of Fiddler Everywhere. It display a summary of each captured session (in the Live Traffic list) and provides functionalities to work with these sessions (through the Live Traffic toolbar, the Inspectors tabs, and the interconnected Rules tab. The section also enables sessions saving and sharing, editing issued requests, marking, commenting sessions, and applying rules.

A Session (also mentioned as a web session) represents a single transaction between a client and a server, sometimes known as for request/response pair. Each session appears as a single entry in the Live Traffic (refer to the images below). Each Session object has a Request and a Response, representing what the client sent to the server and what the server returned to the client. The Session object also maintains a set of Flags that record metadata about the session and a Timers object that stores timestamps logged during the Session processing.

Live Traffic toolbar and list

Live Traffic Toolbar

The Live Traffic toolbar provides various functionalities like streaming mode, decoding content, filtering by different criteria, saving, and sharing sessions.

To start capturing traffic, you need to enable Live Traffic switch to Capturing mode. Use the off switch state to pause the traffic capturing (Paused mode).

The Live Traffic toolbar provides the following functionalities:

Live Traffic Toolbar


By default, Fiddler Everywhere uses buffering mode, which means that the responses are fully collected before any part is sent to the client. Buffering alters the responses (for example, an image won't begin to download until the containing page download is complete). With streaming mode, the server's responses are immediately returned to the client as it is downloaded. In streaming mode, tampering with the response body is not possible.

  1. Click the Stream button to toggle between the streaming and buffering modes.

    Streaming mode is useful for low-level network timing scenarios (for example, by design, some browsers will parse partially-downloaded HTML. That will start downloading external resources in parallel before the remote server has finished delivering the content).

    Buffering mode vs Streaming Mode

    Streaming mode is also useful Ifs where a site delivers audio or video streams. These kinds of never-ending streams can't be buffered by Fiddler Everywhere.

Advanced Filters

Use the Advanced Filters to apply filters based on the Request and Response headers. Only sessions that are covering the filter criteria will appear in the Live Traffic list.

  1. Click the filter button to open the advanced filters popup windows.

  2. The Advanced Filters window allows you to set specific criteria that will filter the captured traffic. Set the filter rules and click Apply.

    Advanced filters popup

Currently, the Advanced Filters entries are using AND logical operator. Each value is complying with the EXACT match.

Alternatively, you can apply filters through the more option on each Live Traffic column (for example, apply a filter for Host column). The column filtering allows using AND and OR logical operators (for two lines), and multiple comparison rules (for example, like Is equal to, contains, ends with, etc.).

Clear All Filters

Use the Clear All Filters to reset all filters applied by Advanced Filters and filters applied for each column (see the columns section)


Use the Save button to save sessions for later use or prepare sessions for sharing.

  1. Click the Save button.

  2. A Save Sessions prompt windows appear. Enter a valid name and click Save.

    Save prompt window

  3. The current entry (of sessions) appears in the Sessions list.

The Save button will automatically save all captured traffic. If you want to keep only specific sessions, you can select the wanted sessions and use the context menu for advanced save options.


Sharing sessions greatly improves collaboration, and Fiddler Everywhere provides several options to export and share sessions:

The toolbar comes with a Share button that will save the currently displayed sessions (captured from Live Traffic) in a file and then shares them through email (provided explicitly).

  1. Click the Share button.

  2. The Save Session prompt window appears. You need to save the sessions before they can be shared.

    Saving before traffic can be shared

  3. The Share Sessions prompt window appears. Enter a valid email (mandatory) and notes (optional) and click on the Share button.

    Share prompt window

Remove All

Use the Remove All button to remove all captured traffic from the Live Traffic list. To remove specific selected sessions, use the context menu

Use the Search text input to search for specific values in the URL and the Headers of all sessions. The search action will immediately filter and show all sessions that are containing the search term.

Live Traffic List

The Live Traffic list is an essential feature of Fiddler Everywhere - it displays a list of web sessions with a summary of each session that the Fiddler Everywhere client has captured.

Live Traffic

Many operations begin by selecting one or more entries in the Live Traffic and then activating other features.

  • To select more than one Session, hold the Ctrl (Command on Mac) or Shift keys while clicking on the desired rows.
  • Double-click or press Enter (Return on Mac) to activate the default inspectors for a single selected Session.

When the Inspectors are activated, they will automatically decide which Inspector is best suited to display the selected session's request and response.

Live Traffic List Icons

The Live Traffic List uses the icons listed below to provide additional context for each recorded session. Hover on an icon on an entry in the Live Traffic list to trigger an explanatory tooltip.

  • Generic document icon - Represents a generic successful response.
  • Uploading icon - Uploading content for a session in progress (the request is being sent to the server).
  • Upload paused icon - Uploading paused for session in progress.
  • Downloading icon - Downloading content for session in progress (the response is being read from the server).
  • Downloading paused icon - Downloading paused for session in progress.
  • Aborted icon - The session was aborted by the client, Fiddler, or the Server.
  • Error icon - The response was a server error.
  • Unauthorized icon - The response returned status code 401 Unauthorized.
  • Redirect icon - The response returned status code 300, 301, 302, 303 or 307 redirect.
  • WebSocket icon - A tunnel used for WebSocket traffic.
  • HTTPS tunnel icon - The request used the HTTP CONNECT method - establishes a tunnel used for HTTPS traffic.
  • RPC tunnel icon - A tunnel used for RPC traffic.
  • No Content icon - No content loaded.
  • Not modified icon - Not modified.
  • Partial content icon - Partial content.
  • Image icon - The response was an image.
  • JavaScript icon - The response was a JavaScript file.
  • CSS icon - The response was a CSS file.
  • HTML icon - The response was an HTML file.
  • Flash icon - The response was a Flash file.
  • XML icon - The response was an XML file.
  • Silverlight icon - The response was a Silverlight file.
  • Audio icon - The response was an audio file.
  • Video icon - The response was a video file.
  • Font icon - The response was a font file.
  • JSON icon - The response was a JSON file.
  • POST method icon - The request used the POST method.

Live Traffic Columns

Certain key information is displayed in the columns of Live Traffic, including:

  • # - An unique identification number generated by Fiddler Everywhere.
  • Result - The HTTP response status code.
  • Protocol - The protocol type (HTTP or HTTPS) used by the session.
  • Host - The hostname and the port of the server to which the request was sent. The column also indicates requests with CONNECT method with Tunnel to value (learn more about CONNECT tunnels in Fiddler).
  • Path - The path refers to the exact location of a page, post, file, or other asset. The path resides after the hostname and is separated by “/” (forward slash).
  • URL - The URL contains the protocol, the hostname, the port and the path from the request.
  • Method - The HTTP Method used by the made request (GET, POST, PUT, etc.).
  • Process - The local OS process from which the traffic originated (for example chrome:8212 indicates a Google Chrome browser instance).
  • Client IP - Indicates the client IP that sent this request. Mostly useful when multiple computers on a network are pointed to a single Fiddler instance.
  • Remote IP - Indicates the IP address of the server used for this request.
  • Body Size - The number of bytes in the response body.
  • Caching - Values from the Response's Expires and Cache-Control headers.
  • Content-Type - The Content-Type header from the response.
  • Time - Indicates the time when the session was executed in HH:MM:SS:ms format.
  • Date - Indicates the date when the session was executed in MM:DD:YYYY format.
  • Duration - Indicates the duration in miliseconds that took for the session to complete.
  • Rules Modified - Indicates if the session is modified by active rules from the Rules tab.
  • Comments A field for showing the custom comments added by you (or the author of a shared session).

Sort and Filter Traffic

By default, the captured traffic is sorted in the order they appear during the traffic capturing (sort by the unique identification number column), and no active filters are applied. You can use the built-in sorting and filtering options to optimize the outcome.

Sorting Options

Create a custom sorting order by clicking the desired column. For example, click the URL column to sort alphabetically based on the URL, or click the Body Size column to sort based on the bytes' session size. The default sorting order is based on the unique identification number (order of appearance).

Filter Options

Each column comes with a more button (three vertical dots), which opens a popup with additional Filter and Columns submenus.

Use the Filter submenu to apply filters for the currently selected column only (for example, filter all the traffic by host name or by a specific status code). Columns with active filters will have a blue filter indicator. You can clear active filters through the Filter popup (for the filtered column) or use the global Clear All Filters button.

Filter context submenu

Use the Columns submenu to select which column will be visible in the Live Traffic list. By default, all columns are visible. Refer to the KB article "How to View Web Session Summary" for detailed information about each column type.

Columns context submenu

Context Menu Options

The context menu for the Live Traffic exposes several actions that can be applied for a Session or multiple Sessions. To show the context menu, press right-click (Windows OS) or Control + mouse-click (macOS).

Live Traffic context menu

Edit in Composer

The context menu option Edit in Composer loads the selected request in a new Composer window where it can be edited, saved (for later usage and sharing), and reissued.


The context menu option Save provides the means to save selected sessions. The saved sessions will appear in the Sessions (the list to the left of the Fiddler Everywhere interface) from where they can be re-opened later, exported, and shared.

  • Selected sessions - Saves all selected sessions. Keyboard shortcut: S.
  • Unselected sessions - Saves all unselected sessions. Keyboard shortcut: Shift + Cmd + S (Mac) Shift + S (Windows).
  • All Sessions - Saves all captured traffic (Keyboard shortcut: S). Keyboard shortcut: Cmd + S (Mac) Ctrl + S (Windows).

All three options will display a save prompt.

  1. Select the sessions, open the context menu, and click the Save option.
  2. Enter your session name and click Save
  3. The saved sessions are immediately loaded in the Sessions list.
  4. Double-click the saved session to load it in the Live Traffic list.

Alternatively, you can save all captured traffic through the Save button from the toolbar


The context menu option Share enables the sharing of sessions. Before any session is shared, it is saved as an entry in the Sessions list. Then the entry can be shared through email.

  • Selected sessions - Saves and shares all selected sessions.
  • Unselected sessions - Saves and shares all unselected sessions.
  • All Sessions - Saves and shares all captured traffic.

All three options will initially display a save prompt and then a share prompt window.

  1. Select the sessions, open the context menu, and click the Share option.
  2. The selected sessions are being saved. Enter your session name and click Save and proceed
  3. The share screen prompt window appears. Enter valid email and optionally add notes. Once ready, click Share.

Alternatively, you can share captured traffic through the Share button from the toolbar


The context menu option Export allows you to export the captured trafcic in different known formats (like SAZ, HTTPArchive, WCAT, MeddlerScript, cURLScript and others).

  • Selected sessions - Saves and shares all selected sessions.
  • Unselected sessions - Saves and shares all unselected sessions.
  • All Sessions - Saves and shares all captured traffic.


Use the Remove context menu options to delete sessions from your Live Traffic list.

  • Selected sessions - Removes all selected sessions. Keyboard shortcut: Cmd + Back (Mac), Del (Windows).
  • Unselected sessions - Removes all unselected sessions. Keyboard shortcut: Shift + Cmd + Back (Mac), Shift + Del (Windows).
  • All Sessions - Removes all captured traffic. Keyboard shortcut: Cmd + X (Mac), Ctrl + X (Windows).


Use the Comment context menu option to add comments for the associated sessions.

  1. Select the sessions, open the context menu, and click the Comment option. Keyboard shortcut: M.
  2. A Comment dialog appears. Enter the comment and click Ok.
  3. The text is added to the comment field for the selected sessions.


Use the Mark context menu option to apply different colors or to strikeout selected sessions.

  1. Select the sessions, open the context menu, and click the Mark option.
  2. Click the preferred marking style to apply it.


Use the Replay context menu option to replay previously captured sessions. Keyboard shortcut: R.


Use the Select context menu option to select sessions directly related to the currently selected session. The possibilities are to choose parent, children, and duplicate sessions.

  • Parent request Selects the session that is a parent of the currently selected session. Keyboard shortcut: P
  • Children requests Select the sessions that are children of the currently selected session. Keyboard shortcut: C
  • Duplicate request Selects the session that is duplicated to the currently selected session. Keyboard shortcut: D


Use the Copy context menu option to place session information in the clipboard. The copied information options are:

  • URL Provides the session URL. Keyboard shortcut:Cmd + U (Mac), Ctrl + U (Windows)
  • FUll Summary Provides verbose session details. Keyboard shortcut: Cmd + C (Mac), Ctrl + C (Windows)

Example for copying URL

Example for copying full info

277 200 HTTP    /fiddler-everywhere/images/livetraffic/websessions/websessions-list-share-options.png   GET 207,094 private, max-age=0, proxy-revalidate, no-store, no-cache, must-revalidate   image/png; charset=utf-8        

Add New Rule

You can use a captured session entry to mock some server behavior. For similar cases, the session URL can be used alongside the Rules tab. Creating rules allows you to test complex scenarios and various mock responses.

  1. Select the desired session entry and make a right-click to open the context menu. From the context menu, select Add New Rule.

  2. New rule is automatically created. The rule will use the URL from the selected session entry and, by default, will apply the initial response through the Return manually crafted response action option.

Additional Resources

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