Saturday, July 14, 2012

Reddit New Comments Highlighter Chrome Extension

So, this is a reddit gold feature which enables a user to highlight all the new comments on a link since he last visited the page.
I have also added keyboard shortcuts Shift+UpArrow & Shift+DownArrow to goto the nearest new comment.

The extension has 2 configurations:

  1. Maximum History: The total number of records to keep in the local storage.
  2. Pixels: The number of pixels to keep above the new comment when the extension scrolls using Shift + Up/Down arrow key.

The Options can of coarse be accessed via Extensions page. The code is available at: & can be installed via Webstore at

TODO: Trigger highlighting when user presses "load more comments" on threads with hundreds of comments.


  1. Thank you for creating this extension. It is basic functionality to which all Reddit users should have access without paying $30/year for Reddit Gold. It's the only way to follow a post with a lot of comments in any meaningful way after the first time you read it.

  2. If anybody wants to change or remove the shift-up / shift-down shortcuts, go to Window › Extensions, copy the ID number under "Reddit New Comments Highlighter", it will look something like "ajdilinnnkbmpoegibgacsdfgblmpjad", then find the extensions folder named like the ID number (under Mac it's Library › Application Support › Google › Chrome › Default › Extensions › ajdilinnnkbmpoegibgacsdfgblmpjad). Find script.js file inside, open in TextEdit or other similar program, find and edit the parts containing shortcut keys on line that will look like this "shortcut.add("Shift+Down", function() {". Personally I just added some random keys to the shortcut, because I'll never use it anyway (Shift+Down+F+D+U+Z). It will probably work only until next update, but I'm guessing this app won't be updated often anyway.

    Cool little extension though.