Difference between events and metrics

  • Updated
  • Optimizely Web Experimentation
  • Optimizely Web Personalization
  • Optimizely Performance Edge
  • Optimizely Feature Experimentation
  • Optimizely Full Stack (Legacy)

Both events and metrics have to do with tracking visitor actions and determining which variations are winning or losing, with some important distinctions.

Use events to track visitor actions like clicks, pageviews, form submissions, and purchases. Events live on pages, which are reusable URL templates that let you choose where campaigns and experiments run. Each time you create a page, Optimizely Web Experimentation and Optimizely Performance Edge automatically create a pageview event for it, but you can also create click and custom events. Events are always on, and you can track them in any experiment—not just the experiment where you create them—so they help you get experiments and campaigns up and running quickly, which saves you time.


Events are specific to projects. In Optimizely Web Experimentation, Optimizely Performance Edge, and Optimizely Web Personalization, events are listed under Implementation > Events.

In Optimizely Feature Experimentation and Optimizely Full Stack (Legacy), events are listed on the Events page.


After you add events to a campaign or experiment, they become metrics. Metrics help you measure differences in visitor behavior based on changes you make to your site in experiment variations or personalized experiences. The event you choose as your primary metric determines which variations are winning and losing.

To find metrics for individual experiments, select an experiment and click Metrics.

Create events