Skip to main content

De-obfuscating javascript code in Chrome Developer Tools

I had blogged about JavaScript debugging with Chrome Developer Tools some time back, wherein I have explained how these developer tools can help in debugging javascript code. Today Google Chrome 12 was released and my Chrome browser was updated to this version. As with every release, there have been some improvements made on performance, usability etc,. One feature that stood out for me is the ability to De-obfuscate the javascript code.

What is Minification?

Minification is the process of removing unnecessary characters such as white spaces, comments, new lines from the source code. These otherwise would be added to make the code more readable. Minifying the source code helps in reducing the file size and thereby reducing the time taken to download the file. This is the reason why most of the popular javascript libraries such as jQuery are minified. A minified jQuery file is of 31 KB in size where as an uncompressed one is about 229 KB. Unfortunately, debugging minified javascript files is an impossible task.

With the latest version of Google Chrome one can choose to de-obfuscate the javascript code right with in the developer tools. This is how the jquery.js file would look before de-obfuscation:



Now, to de-obfuscate the code one can right click on the file and select the 'De-obfuscate Source' option. This would de-obfuscate the javascript code and present the code which is readable and ready to debug:



Update:

This post was written when Chrome 12 was released. In recent versions, this option is available as a button - 'pretty print', at the bottom left corner of the screen. Look for the button with the icon '{ }'.


Labels:

Comments

  1. Exist-DissolveJune 17, 2011 at 9:09 PM

    I don't have an option for de-obfuscating the code, but I do have a new "Pretty Print" option next to the Pause Exceptions option. Seems to do the same thing.

    ReplyDelete
  2. Sagar GanatraJune 17, 2011 at 9:45 PM

    You can right click anywhere on the javaScript and you should have 'De-obfuscate Source' option there. Are you on Chrome 12?

    ReplyDelete
  3. Exist-DissolveJune 17, 2011 at 11:40 PM

    Ah, nevermind. I'm on 14

    ReplyDelete
  4. Adelein RodriguezAugust 9, 2011 at 6:48 AM

    in chrome 13 and above it is a { } on the bottom right corner of the screen

    ReplyDelete
  5. Sagar GanatraAugust 9, 2011 at 9:37 AM

    @Adelein,

    You're right, they have now provided the option pretty print.

    ReplyDelete
  6. AnonymousOctober 18, 2011 at 5:12 AM

    Oops, that's *bottom left* .. the curly brackets :)

    ReplyDelete
  7. Sagar GanatraOctober 18, 2011 at 9:22 AM

    I have update the post with the option available in recent version.

    ReplyDelete

Post a Comment

Popular posts from this blog

File upload and Progress events with HTML5 XmlHttpRequest Level 2

The XmlHttpRequest Level 2 specification adds several enhancements to the XmlHttpRequest object. Last week I had blogged about cross-origin-requests and how it is different from Flash\Silverlight's approach .  With Level 2 specification one can upload the file to the server by passing the file object to the send method. In this post I'll try to explore uploading file using XmlHttpRequest 2 in conjunction with the progress events. I'll also provide a description on the new HTML5 tag -  progress which can be updated while the file is being uploaded to the server. And of course, some ColdFusion code that will show how the file is accepted and stored on the server directory.
18 comments
Read more

Server sent events with HTML5 and ColdFusion

There are several ways to interact with the server apart from the traditional request\response and refresh all protocol. They are polling, long polling, Ajax and Websockets ( pusherapp ). Of all these Ajax and Websockets have been very popular. There is another way to interact with the server such that the server can send notifications to the client using Server Sent Events (SSE) . SSE is a part of HTML5 spec:  http://dev.w3.org/html5/eventsource/
19 comments
Read more

Adding beforeRender and afterRender functions to a Backbone View

I was working on a Backbone application that updated the DOM when a response was received from the server. In a Backbone View, the initialize method would perform some operations and then call the render method to update the view. This worked fine, however there was scenario where in I wanted to perform some tasks before and after rendering the view. This can be considered as firing an event before and after the function had completed its execution. I found a very simple way to do this with Underscore's wrap method.
Post a Comment
Read more