Fiddler – The missing string of Web Development – Part I

This is the 1st post of the 3-part-series on using Fiddler. Please visit the Second, and Third post for more insight

Working as a UI dev for any enterprise software programming language e.g. Java or .Net could be tedious.

If you’ve worked in a Java Environment before, you must have known – Every time you make changes to JavaScript or CSS, you may need to make another build, clear cache or restart the server, may be clear some cookies or session data. All of this happens on your local machine (Thankfully. And this means you can always edit the static files in the tomcat’s web ROOT directory)

But what if your code is on a development server (where builds are triggered after, say every post-update event or post-commit event or periodically every hour)? You may not wish to push your code, trigger another build into the queue and wait – just after fixing some minor changes. There might still be errors that you’ve not identified.

So, won’t it be nice if we could make CSS or JS changes without any ado? And, that too, on your machine, locally?

Fiddler saves your day.
How ? Well, 3 simple steps.
1. Go to ‘Auto Responder’

2. Go to Rule Editor at the bottom
Rule Editor
– Type “EXACT:
– There is a drop-down below, go to the last of it & click on ‘Find a file…’
– Choose your local version of JS file ( that you just made changes into)
3. Save. Make sure you have checked ‘Unmatched requests pass through’.
Unmatched Req Pass Thru
All done. Keep calm & hit ‘CTRL + shift + R’ in your browser.

What does fiddler mean to me?
Answer: A JS and CSS file replacer, and occasionally a Web Service response replacer

Fiddler acts like a proxy server inside your machine.
And it captures:
– every HTTP request generated from you machine
– and, every response received
+ plus, it let’s you fiddle with them.

The changes that would have reflected after building, cache clearing, server restarting – are now available just a RELOAD away.

If you are a web developer, Fiddler is the must one in your tool kits.
Fiddler tutorial –

If you need a detailed guide, you may follow the link for a complete tutorial.

Fiddler can do a lot more than just replacing files. I’ll keep publishing them as I explore more about them.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s