Vue devtools

An official debugger tool for Vue is available on Chrome as an extension called Vue.js devtools. It can help you see how your app is running to help you debug your code. You can download it from the Chrome Web Store (https://chrome.google.com/webstore/search/vue) or from the Firefox addons registry (https://addons.mozilla.org/en-US/firefox/addon/vue-js-devtools/?src=ss).

For the Chrome version, you need to set an additional setting. In the extension settings, enable Allow access to file URLs so that it can detect Vue on a web page opened from your local drive:

On your web page, open the Chrome Dev Tools with the F12 shortcut (or Shift + command + c on OS X) and search for the Vue tab (it may be hidden in the More tools... dropdown). Once it is opened, you can see a tree with our Vue instance named Root by convention. If you click on it, the sidebar displays the properties of the instance:

You can drag and drop the devtools tab to your liking. Don't hesitate to place it among the first tabs, as it will be hidden in the page where Vue is not in development mode or is not running at all.

You can change the name of your instance with the name option:

var app = new Vue({
  name: 'MyApp',
  // ...
})

This will help you see where your instance in the devtools is when you will have many more: