View change history

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

You can view the change history for your projects and identify changes that might have caused problems with your experiments.

Optimizely Experimentation logs most actions you can perform for a project, like creating a page, modifying a variation, and adding and removing audiences. These actions are listed in the change history, which shows the record of user activity for each of your projects.

If an experiment starts to behave strangely or stops working correctly, you can troubleshoot by checking the change history to see the changes that were made, when, and by which collaborator. The change history creates an activity trail that provides additional security to individuals and teams with multiple collaborators.

Change history is located in the same location within the Optimizely Experimentation App for Optimizely Web Experimentation and Optimizely Feature Experimentation. The following images uses Optimizely Feature Experimentation, but the steps are the same in Optimizely Web Experimentation.

Each project’s history is listed under History:


Open the Show details drop-down list to see changes. 


Use the drop-down lists at the top of the page to filter the History displayed by the Type of change or select Date to view the history in a time frame. 


View change history in Optimizely Web Experimentation

The following table shows the changes Optimizely Web Experimentation saves in each project's change history:

Feature Changes saved
  • Created
  • Archived
  • Unarchived
  • Modified name, description, or conditions
  • Created
  • Modified
  • Created
  • Modified
  • Created
  • Archived
  • Unarchived
  • Modified name or description
  • Changed variation:
    • Changed element
    • Inserted HTML or image
    • Added redirect
    • Changed variation CSS or JavaScript
  • Changed shared code (JavaScript or CSS)
  • Added or removed page
  • Added or removed event
  • Changed primary metric
  • Changed traffic allocation
Project JavaScript All changes

In general, the change history detail panel displays the original (before changes) in red on the left side and the updated code (after changes) in green on the right side.

The following sections show change detail examples to demonstrate the information listed for changes to different features.

Audience Conditions

For each audience condition, you will see type and value keys. Check the values for these keys for the specific changes made to the audience.


Change history displays changes to Apply JS, Reset JS, HTML, and CSS in the extension builder.

Variation changes made with the Visual Editor

For changes made to elements using the Visual Editor, a full code representation of the Visual Editor change is visible, so you will look for the property or attribute that was actually modified. In this example, font-weight was set to "bold."

In the following example, the value for the html key was changed from "Gear for Fall" to "Gear for the cooler months."

Variation changes made with the Code Editor

Change history displays changes to CSS and JavaScript code made with the code editor.

View change history in Optimizely Full Stack

See the developer documentation for the list of changes saved for Optimizely Full Stack Experimentation.

View change history in Optimizely Feature Experimentation

See the developer documentation for the list of changes saved for Optimizely Feature Experimentation.