Itsy / Themes / How-To

If you know CSS, you can make your own themes to customize the way Itsy looks.

What is a theme?

A theme is a folder named with the extension ".itsy". You can name the folder whatever you want as long as it ends with the extension ".itsy". We'll call this folder the theme package.

A theme package contains the following:


The Info.plist property list is an XML file which contains the following fields:


The CSS file that defines your theme must be named "styles.css". It is just a regular CSS file. One important point is that you must provide a scrollbar style. If you don't, Itsy will get confused when a user switches between your theme and others. To style the scrollbar, use the Webkit scrollbar CSS pseudo-elements.

HTML Inspection

You can use a tool called WebKitInspector to see Itsy's HTML. Here's how:

  1. Quit Itsy
  2. Open the Terminal application
  3. Type this command: defaults write com.mowglii.itsy WebKitDeveloperExtras -bool true
  4. Open Itsy
  5. Right-click on a tweet and choose Inspect Element
  6. If the Inspector opens in the bottom of the Itsy window, click the button in the lower left to pop the Inspector into it's own window


Installing a theme is very easy. Once you have created your theme package simply double-click it. This will copy the theme package to Itsy's Application Support folder. Itsy will launch with your new theme activated. That's it.

Sample theme

To get you started, here is a sample theme: Itsy Light. If you use this theme as a starting point, remember to edit the Info.plist file and change all the fields.