Sybu JavaScript Blocker – Google Chrome Extension


Sybu JavaScript Blocker is a Google Chrome Extension to quickly block JavaScript (JS) files from being loaded by the browser.

It has been designed to be easy to use.



Install from Google Chrome Web Store


After you have installed the extension.  It will be visible to the right of the Chrome search/address bar.


It is a little blue shield icon. Click the icon.

The Sybu JavaScript Blocker has 3 modes:  OFF | My Rules | Block All


Mode:  Off


The extension is disabled and will not block any JavaScript files

Mode: My Rules


Block 3rd Party scripts
When enabled,  the script will block JavaScript files that are not from the same domain as as the requested page.  This will immediately block a lot of trackers and advertising links, without the need to specify individually.

See example below.

Here the plugin block all JS items not originating from domain  as the requested page was


To define specific/custom Rules click the Rules button

Rules  section > Block List
The extension will then block files containing the specified text.

Rules  section > White List
The extension will then white list (allow) files containing the specified text

Enter your rules in the text areas, this can be a full URL, or any part of it, as shown below. Press ‘Save and Reload’ when done.


Rules can also be added by clicking  on the [+]  [-]  [-WL]  button next to the listed JavaScript file

[+]  Add to Block list
[-]  Add to White list
[-WL]  Remove from White list



In this example in you choose

1: ga – This will block any JavaScript on any page that contains ga as part of the URL

2: ga.js – This will block the JavaScript with filename ga.js on any page

3:    – This will block JavaScript on any page originating as

4:   – This will block any Javascript originating from domain

5: Other.  This will block any JavaScript on any page that contains the specified text as part of the URL

To unblock a file (remove the block rule) click on the [-] button next to the file being blocked.
or simply remove the text from list of items in Block List


This display the rule associated with blocking this file and prompt you if it must be removed.


Mode: Block All

In this mode all JavaScript will be blocked, but you will find that most pages do not render properly.  So options are available to allow some JavaScript to be loaded. Exceptions can be Added in Allow Rules > White List

So for example it may be useful not to block a script like jquery since this is used on many websites to display content dynamically. An example is shown below where jquery is not blocked.




The list of JavaScript files loaded and blocked by the browser is shown at the bottom of the dialog.


sd_jsblock_120_06b JavaScript file was loaded

sd_jsblock_120_06cJavaScript file was blocked

1,2,3.. The numbers next to listed items indicated the loaded sequence

sd_blocker_indicator The total number of files blocked.  Click to sort.


 Click to edit the Block List, White List.   It also indicates the number of rules for block and white list items.

 File is currently allowed. Add block rule.

 File is currently blocked. Remove block rule

 File is currently allowed.  Remove the white list rule



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