SYBU JavaScript Blocker – What is new



v2.97 – 7 May 2021

  • Minor UI improvements, typography [SJB-1]
  • Added tooltips to controls on rule screen, to provide explanation of the selection. Hover over control for about 1sec to display tip [SJB-3]

v2.95 – 5 May 2021

  • Update: No Cache Reload option added.  This will instruct the browser to reload the page, but not to load any scripts from memory cache.  
  • Improved detection and blocking of Service Worker scripts. Some websites may install a Service Worker script, which again may load further JS scripts.  These scripts may be linked to several tabs.  
  • Options for temporary rules added.
  • Temporary allow rules added
    If you do not want to set a permanent rule.  Then a temporary rule can be set. This is useful for sites that you don’t visit frequently. Click the button with clock icon to display options.

  • Specific temporary allow rules can also set for individual scripts 
  • Allow rules for temporary allow sites and scripts can be viewed or cleared

v2.94 – 18 March 2021

  • Update: User Interface updated to current Bootstrap and jQuery versions
  • Update: User Interface layout changes.
    Dark mode option moved to Options dropdown menu.
    Advanced Regular expression moved to Block Rules panel
  • New : Good / Bad Sites.
  • Good Sites – All scripts will be allowed that the site requests
    Bad Sites – All scripts will be blocked that the site requests
    Sites can quickly be added by using the ‘Add Good‘ , ‘Add Bad‘ buttons
  • New option was added for Block Rules and Allow Rules to apply a rule only to a request that originated from a specific domain, -or- to all sites.
    In this example below we are visiting,  which is loading a script element.js from
    we now have option to block element.js  for all sites,  or only when visiting   
    The Block Rules will be updated to include the domain, as shown below

v2.93 – 25 January 2020

  • New: Advanced Block Rules can be specified using regular expressions. Click on the Rx(.*) button.
  • Bugfix: Some users may have been impacted with failed “Import Rules” – the issue has been resolved.
    Import failed. Original settings restored. Error reported: SyntaxError: Unexpected token , in JSON at position" xxxx.

v2.92 – 23 September 2019

  • New Options menu has been added on right side of form.

  • New. Export Rules.  All rules can be exported to a file.  The file is automatically saved in the web browser’s Downloads folder.   The filename is automatically generated, starting with SybuJsBlocker-[Bx-Ax-Wx]-<date>.json
  • New. Import Rules (Replace).  An exported file can be imported.  This will replace all existing rules.
  • New. Import Rules (Merge). The file being imported will be merged with existing rules.  If the rule does not exist, it will be added.  If the rule already exist, it will not be added.
  • Fix. When a URI contained an @ character and depending its position within the URL, the Hostname may have been incorrectly derived.
  • Fix. Minor bug fixes

v2.91- Release – 22 July 2019

  • New. Darkmode. Option to switch theme.

  • Bug. Fix issue related to reporting the incorrect blocked count and Url for the last focused browser tab, when multiple tabs across multiple Chrome windows have been opened.

v2.81- Release – 21 April 2019

  • Bug.  Fix issue that resulted in removal of website images.  Introduced by update v2.80
    Apologies for causing this issue.

v2.80 – Release – 19 April 2019

  • Google requested an update to the plugin, to comply with their new terms of use.

v2.70 – Release – 7 November 2018

  • Added Whitelisted Domains in My Rules.  This will ignore any rules for the specified domain (similar to Off mode). All scripts that the website request, will be loaded.  Examples for websites that this may be useful is:,

v2.60 – Release – 16 May 2018

  • Improved User Experience, to distinguish and manage Block Rules and Allow Rules easier in the My Rules Blocking Mode.
  • Added the display of the specific rule (below the JS url),  that blocked or allowed each script.
  • Added a page reloading indicator when the interface is open, while the user or the plugin performs a page refresh
  • Fixed bug in reported blocking count when website requested same JavaScript files multiple times.
  • Updated the instructions.

v2.50 – Release – 4 April 2018

  • Improved User Experience when swapping between tabs that was previously opened,  when displaying the list of Blocked and Allowed files.
  • Fixed bug in sorting of Blocked Items  (when Blocked button was clicked)
  • Improved display of Badge icon.
  • Add display of version number and added link to What is new in the release.

v1.00 – 15 March 2016

  • Initial release

Setup Instructions

gear2Setup instructions here