TLDR? – Get the newest Fiddler here. We’re performing a staged rollout of this build; it won’t be on autoupdate until next week. Under the Hood As mentioned in our notes about the Fiddler 4.6 release, we’ve started taking a very close look at Fiddler’s performance. Fiddler’s use of the CPU, system memory, and theContinue reading “What’s New in Fiddler 4.6.0.7”
Tag Archives: Fiddler
Viewing HTTPS Handshakes in Fiddler
You can easily use Fiddler to evaluate what algorithms a client is using to connect to a HTTPS server in Fiddler. First, adjust Fiddler’s configuration using Tools > Fiddler Options to enable capture of CONNECT tunnels but disable decryption: Disabling decryption is necessary because Fiddler decrypts traffic using a HTTPS man-in-the-middle technique, which means thatContinue reading “Viewing HTTPS Handshakes in Fiddler”
Fiddler and Brotli
Regular readers of my blog know how excited I am about Google’s new open compression engine, Brotli. Support is in Firefox 44 Nightly already and is expected for other browsers. Because Brotli is used inside the WOFF2 font format, many clients already have the compression code and just need to expose it in a newContinue reading “Fiddler and Brotli”
Fiddler Certificate Generators
Fiddler and FiddlerCore offer three different choices for generating interception certificates: MakeCert CertEnroll Bouncy Castle If you’re so inclined, you can even write your own certificate generator (say, by wrapping OpenSSL) and expose it to Fiddler using the ICertificateProvider3 interface. On Windows, Fiddler includes the MakeCert and CertEnroll certificate generators by default; you can downloadContinue reading “Fiddler Certificate Generators”
What’s New in Fiddler 4.6
Telerik Fiddler version 4.6 (and v2.6 targeting .NET2) is now available for download. The new version includes several new features and dozens of tweaks and bugfixes, described in this article. View > Tabs Menu The new View > Tabs menu offers a list of tabs that are hidden by default. The Preferences command displays aContinue reading “What’s New in Fiddler 4.6”
API Testing with Telerik Fiddler
Fiddler has long been the tool of choice for developers and testers who are building and verifying APIs exposed over HTTP(S). In this post, we’ll explore the existing features Fiddler offers for API Testing and announce new capabilities we’ve released in Fiddler 2.6/4.6. Composing API Calls The Composer tab enables the authoring of arbitrary HTTP(S)Continue reading “API Testing with Telerik Fiddler”
Tuning MemoryStream
By day, I build the Fiddler Web Debugger. I’ve recently started integrating telemetry collection into the application for automated exception reporting and to collect information about the user’s environment to ensure that Fiddler testing environments match real-world usage. The data is fascinating (and I’ll probably blog more about it later), but one data point inContinue reading “Tuning MemoryStream”
Testing HTTPS In Native APPs
Over on Twitter, Paul asks how to verify that a native application is using TLS. For a PC, it’s pretty simple, just run Fiddler and watch the traffic. If you see any HTTP requests (other than those labeled “Tunnel to”, indicating a HTTP tunnel used for HTTPS traffic) from the Process of interest, that trafficContinue reading “Testing HTTPS In Native APPs”
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