How to set custom variables through the new analytics.js of GA

Solution 1:

Custom Variables don't exist any more in analytics.js (aka Universal Analytics). It has been replace with Custom Dimensions and Metrics that are more flexible and powerful.

Advantages of Custom Metrics and dimensions:

• They can be used in filters
• They are first class citizens in the interface, so you will see the custom variable name in the interface (instead of the generic "Custom Variable 5")
• Configured in the interface
• Metrics that are aggregated (not possible with custom vars)
• 20 custom dimensions + 20 custom metrics available, instead of only 5 custom variables

In order to use Custom Dimensions/Metrics, you need to configure them on the interface. Go into admin, drill down into your web property and then there is a tab for "custom definitions".

Then when you track it, you just need to track the value and the id of the custom property eg:

ga('send', 'pageview', {
  'dimension15':  'My Custom Dimension'
});

This will send a pageview with the custom dimension attached to it.

You can also set one on the page that will be applied to any pageviews or events that happened on the page.

ga('set', 'dimension5', 'custom data');

Note that only setting it won't send to GA, so if you decide to use set make sure you call a send afterwards at least once on the page to actually send that data to GA.

More Info: Developer Docs