Introducing …. neXpert

What is it?

 neXpert is an add-on to Fiddler Web Debugger which aids in performance testing web applications.  neXpert was created to reduce the time it takes to look for performance issues with Fiddler and to create a deliverable that can be used to educate development teams.

neXpert can be downloaded here:

A webcast showing a demonstration of neXpert can be watched here:

What are the features?

·         Add step markers while capturing traffic to create steps or clicks in a scenario

·         Easy access buttons for performance testing with Fiddler

o   Clear Cache/Cookies

o   Enable Fiddler Streaming Mode (

·         Ping each host in a capture to calculate current latency

·         Create rudimentary response time predictions for different latencies and browsers (BETA)

·         Create a HTML report which checks for performance issues with the following:

o   HTTP Response Code

o   ASP.NET View State

o   Static Files

o   Large Images

o   Compression

o   Authentication

o   ETags

o   Cache Headers

o   Connection Header

o   Vary Header

o   Cookies

What resources are on the blog?

The left toolbar provides links to other performance-oriented blogs you may be interested in.

There is also a link to the “Known Issues” page which will be used to track any issues found in the most current public build.  If you have found any issues, please use the “Send Feedback…” option located in the neXpert menu in Fiddler. 

What will this blog be used for?

This blog will be used primarily for discussing neXpert and how it can be used to help performance test your web applications.  This will include such things as upcoming features, how to implement neXpert into your testing and how to fix the problems neXpert finds. This blog will also be used for discussing performance testing with Fiddler as well as general web performance issues.

You can subscribe to this blog using the syndication links on the left toolbar.  For information on how to use Outlook to subscribe to this blog, please click here:

This is NOT Fiddler’s blog.  Fiddler was created by Eric Lawrence and you can find links to the official Fiddler resources including a blog on the left toolbar.

 Update: Added webcast link

Comments (6)

  1. Thank you for submitting this cool story – Trackback from DotNetShoutout

  2. hatchan says:

    I tried installing neXpert on my computer at work, but the installation fails with the following message: "Could not access network location \servernameuser$username\Fiddler2Scripts." (where ‘servername’ and ‘username’ are replaced by the real values). The path does not exists because of the double slash in the middle of the path. The path with just 1 single slash does exist. Is there something I can do or do I need a new installer?

  3. nexpertb says:


    Sorry for your issue.  The installer just copies the necessary DLL and help file into the Fiddler2Scripts directory. Nothing else.  If you can get it installed on another computer, you can just copy the 2 files from that computer to your work computer.  You could easily do this if you have a Virtual PC available on your work computer.  If you are still having issues, please email us directly using the Email link in the "This Blog" section in the top left.

    Again, sorry for the issue but thanks for reporting this.

  4. hatchan says:

    I installed it on a other computer and grabbed the files and copied them to the my documents folder. Off course then code access security didn’t like it that I ran the dll’s from a network path, but I fixed that. Now everything works, so thanks.

  5. says:

    Note: Cross posted from Sajay . Permalink Here is a quick way to get an idea of how long your request/response

  6. Sanu says:

    Hi All,

    I have installed neXpert plugin to my Fiddler v4.4.6.2

    However, while recording the script using Fiddler, i am unable to find any step names marked in the "Step" column.

    Please clarify.

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