* Are you a software developer working on a Mac?
* Do you ever get Fiddler session archives from a customer having an issue with your software?
* Have you ever wanted to view these archives in a native Mac app next to your editor window?

Netopsy is an app for viewing network traces (SAZ files) created by the Fiddler web debugging proxy.

* Quickly open an archive and zero in on failed sessions
* View requests and responses in multiple formats to debug issues at various levels of your stack
* Use multiple documents for comparing sessions from multiple users.
* Open large archives with thousands of recorded sessions

What’s New

Version 1.5.0

New Modern UI!

- Sessions can be filtered by matching against the URL
- Requests and responses are split top and bottom to be shown at the same time
- Raw format view includes HTTP headers
- All text formats include line numbers
- HTTP Status codes are given a color corresponding to success or failure

In addition, some pesky bugs have been fixed.

Thank you for your feedback!

Ratings and Reviews

5.0 out of 5
1 Rating

1 Rating

tberry2112 ,

Awesome tool to open Fiddler .saz files directly on my Mac!

Thanks Dave, this is exactly the tool I have been looking for! Thanks for releasing a handy tool for opening Fiddler capture files without having to launch a VM and get on Windows, or use the mono version on Mac


Dave Weston
5.8 MB
Developer Tools

OS X 10.10 or later, 64-bit processor



Age Rating
Rated 4+
© 2018 Dave Weston


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.