Debugging Web apps for free with Fiddler

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There comes a time in every tech’s life when he or she must debug their organization’s Web “stuff.”Luckily, there’s a ton of tools available for this task. Unluckily, there’s so many it’s hard to know which to choose. Let me make it simple for you with a Web debugging tool that’s not only amazingly good, but is also free.

The tool, published by Telerik, is Fiddler, a web proxy designed for debugging. This software is amazingly versatile and has established versions for Windows as well as alpha builds for Linux and OS X (which have run “(more or less) successfully on Ubuntu 12/13, Linux Mint 15, and OSX 10.8”). The Windows versions rely on and are specific to various versions of the .NET framework (if you’re not certain which framework you’ve got installed you might check out Microsoft’s support note on the topic).

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Fiddler’s main window

Once installed (which is completely straightforward) you’ll be able to launch Fiddler, configure it, and from within the program download the syntax analysis add-on which provides syntax-highlighting for HTML, JavaScript, CSS, XML and other web content formats as well as adding rule editing support.

You can also download any of the other add-ons, which include image manipulation, a PDF inspector, a JavaScript formatter, a privacy scanner, a traffic differ (to compare traffic profiles), and a security auditor. Even better, if you have special needs you can even develop your own Fiddler add-ons using any .NET-supported language.

Fiddler Core, Fiddler’s proxy engine, can be integrated into third-party applications and using Geoedge you can Fiddler and the Geoedge global proxy network to monitor, inspect, and debug traffic from over 130 locations.

Now you have all the tools needed to perform Web debugging (ensuring the transfer of the required cookies, headers and cache directives), web session manipulation, performance testing, security auditing, and HTTP/HTTPS traffic recording. Just hope your boss hasn’t read this review otherwise he’ll want to know what the hold up is. Why hasn’t that app been fixed already?

Fiddler is, in short, a Swiss Army Knife for Web client and server analysis and debugging. This is a fabulous tool that absolutely should be in your toolkit. Fiddler gets a Gearhead rating of 5 out of 5.

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