Rules Editor

The Rules Editor interface enables creating and editing rules. You need to enter a match rule and an action string, and Fiddler Everywhere will undertake the action if the request URI matches the match rule.

Auto Responder button

Create New Rule

  1. Click on Create New Rule button in the Rules Editor. Create New Rule button
  2. Enter a match rule. See the match rule section for more details. New Match Rule
  3. Enter an action string. See the action string section for more details. New Action String
  4. Add the newly created rule to the Queue Viewer list of rules.


  • Rules are applied in the order that they appear in the Queue Viewer. Hit the Down Arrow to demote a rule.
  • You can export the current queue of rules via the Export button from the Queue Viewer toolbar.
  • You can import a *.FARX file via the Import button to queue rules based on previously captured traffic.

Match Rules

Fiddler Everywhere will accept string literals, regular expressions, and a set of some special match rules as listed below.

String Literals

NOT rules (for String Literals)

The NOT: rule is applied only if the string does not match.

  • NOT:EXAMPLE - Will match URLs that do not contain the EXAMPLE string. // (MATCH)
  • NOT:path1/ - Will match URL that do not contain path1/.
NOT:path2/ // (MATCH) // (No Match)
  • NOT:query - Will match URLs that do not contain query.


The EXACT: is a case-sensitive match syntax for expressions and strings.

  • EXACT:URL - Will match URL that is identical to the passed URL parameter. Note that the EXACT: rule is case-sensitive. // (MATCH) // (No Match - mismatched case)

Regular Expressions

Fiddler Everywhere supports regular expressions syntax for expressions that begin with regex:. The regular expression will be used to replace the inbound URL with the string in the Actions row. Use .+ to match a sequence of one or more characters or .* to match zero or more characters. Use ^ at the front of your regex to mean "Start of the URL" and use $ at the tail of the regex to mean "End of the URL".

  • regex:.+ - Will match all URLs // (MATCH)
  • regex:.+.jpg$ - Will match URLs that are ending with .jpg // (MATCH) // (MATCH)
  • regex:.+.(jpg|gif|bmp)$ - Will match URLs that are ending with the listed image extensions (case-sensitive!). // (No Match - imnproper ending) ple.jpg // (MATCH) // (No Match - mismatched case) // (MATCH)

Action Strings

Beyond simply returning files, the Auto Responder can perform some specific actions:

Action String Description Action Type
filename Return contents of the filename as the response. Final
http://targetURL Returns the content of the targetURL as the response. Final
*redir:http://targetURL Returns a HTTP Redirect to the target URL. Unlike the simple URL rule, this ensures that the client knows where its request is going so proper cookies are sent, etc. Final
*bpu Breaks on request before hitting the server. Non-final
*delay:#### Delay sending request to the server by #### of miliseconds. Non-final
*header:Name=Value Set the Request header with the given Name to the specified Value. If no header of that name exists, a new header will be created. Non-final
*flag:Name=Value Set the Session Flag, with the given Name to the specified Value. If no header of that name exists, a new header will be created. Non-final
*CORSPreflightAllow Returns a response that indicates that CORS is allowed. Final
*reset Reset the client connection immediately using a TCP/IP RST to the client. Final
*drop Close the client connection immediately without sending a response. Final
*exit Stop processing rules at this point. Final

Rules with Non-final actions will allow the request to match multiple Auto Responder rules. As soon a rule specifying a final action is reached, the matching process exists, and no further rules are processed for that session.

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