m. c. de marco: To invent new life and new civilizations...


Bicolorize is a bookmarklet for bicolorizing text, inspired by the Lazy Eye Reader formerly at Lazy Eye Games. (There's now one Lazy Eye Training.) When viewed with anaglyph (3D) glasses, half the letters will be visible to one eye and the other half to the other eye. For this to work, the background also needs to be a fixed color, which the bookmarklet sets.

You can also play bicolor tetris here or at Lazy Eye Tetris.


Some before-and-after text to show how it comes out:


To configure the bookmarklet (and Tetris), select your anaglyph glasses style, and then check the preview to make sure that one color is invisible in each eye. You can tweak the colors or enter your own by clicking on the other option. You can also set your background color and the number of letters you want per chunk of text.

invisible left text invisible right text
Anaglyph glasses:

Install the Bookmarklet

To install, drag this link to your Favorites or Bookmarks bar: Bicolorize.

To install directly on an iPhone or iPad, you can follow these instructions on adding a bookmarklet to Mobile Safari, but I find it's easier to add the bookmarklet to desktop Safari and let iCloud sync it. (Syncing can be set up under Settings | iCloud | Safari on iOS, and System Preferences | iCloud | Safari on MacOS.)


Go to a web page you want to read and click the bookmarklet. The text should be transformed as in the demo below. To undo, reload the page.

The bookmarklet will also colorize some iframes. If you have trouble with an iframe, open it in a separate window or tab and try the bookmarklet again.

Play Tetris

You can also play Tetris using your configuration settings. The code is available on Github.