Filters Reference

Fiddler's Filters tab allows you to easily filter and flag traffic displayed in the Fiddler UI, as well as do some lightweight modifications.

Trim

The Keep only the most recent # sessions box enables Fiddler to discard older sessions beyond the specified threshold.  This reduces memory usage and helps improve performance.

Hosts

The Hosts filter enables you to flag or exclude display of traffic to specified fully-qualified domain names.

Note that Fiddler when configured to exclude hosts, will still proxy traffic to those hosts, but that traffic will be hidden from the Fiddler Session List.

Client Process

The process filter allows you to control which processes' traffic is shown within Fiddler.  Note that Fiddler will still proxy traffic sent to it from other applications, but that traffic will be hidden from the Fiddler Session List.

Breakpoints

The breakpoints enable you to break requests or responses that contain the specified attributes.

Request Headers

Using these options, you can add or remove HTTP request headers, and flag responses that contain certain headers.

You can also filter displayed traffic down to specific URLs with the Show only if url contains box. You can demand case-sensitivity with the EXACT directive

    EXACT://example.com/q=Case+Sensitive+String 

or you can use regular expressions, so you can use:

     REGEX:(?insx).*\.(gif|png|jpg)$ #only show requests for img types

Response Status Code

Using these options, you can filter display of responses based on the Response Status Code.

You to hide sessions whose responses code match target values [HTTP errors, redirects, authentication challenges and cache-reuse].

Response Type and Size

Using these options, you can control what types of responses appear within the session list.

The list of "Block" checkboxes enables blocking responses of the specified types, returning a HTTP/404 error to the client instead of the target resource.

Response Headers

Using these options, you can add or remove HTTP response headers, and flag responses that contain certain headers.