What's the Difference Between a Chrome App and an Extension?

The Chrome web browser and Chrome OS introduce a new way to think about browsing the Web. Traditional browsers have extensions and themes, but what is this new web app idea for Chrome? What's the difference between that and an extension?

Web Apps

Web apps are basically websites. They run within Chrome's browser using things like javascript and HTML, and they may not even require any downloads. Sometimes they may need to install a small component on your local machine, but that will only make a difference when you're using that particular web app.

An example web app would be Google Maps. It runs within the browser and doesn't require you to download anything, but it has its own user interface. Gmail or Inbox (when you use them within the browser window) are also web apps, as is Google Drive. 

In the Chrome web store, you can choose between web apps that are websites and those that are Chrome apps. You can also filter to choose web apps that run while the computer is offline. 

Install web apps on Chrome by:

  1. Browse the Chrome web store and find the desired web app
  2. Click on the app preview to bring up a description, screenshots, reviews, and compatibility information. 
  3. If everything looks good, click on Add to Chrome.  


An extension, on the other hand, affects something global on your browser. For instance, an extension may add the ability to save items to your Amazon.com wish list. When you install the extension, that feature is available on every single site you visit, not just on Amazon.com.

Another example is the Chromecast extension "Google Cast," which allows you to broadcast your browser tabs to your Chormecast connected TV. 

Install extensions for Chrome by:

  1. Browse the Chrome web store and find the desired extension (optional: use filters to refine your results while searching)
  2. Click on the extension preview to bring up detailed information about the extension and reviews. 
  1. If everything looks good, click on Add to Chrome. 


Themes are used to personalize the appearance of your browser, such as by changing the color scheme or changing the background. This can be powerful since you can change the appearance of everything from the tabs to the scrollbar. However, changing your theme does not change the basic function of those items beyond the appearance. 

Install themes by browsing from the Chrome web store and following the same basic directions you'd use for extensions or web apps. 

Extensions use downloaded components to modify your browser. This is a contrast to themes, which do modify your browser but only by changing the appearance of elements like the background and fonts used.   

You can find apps, extensions, and themes at the Chrome Web Store.