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Cookies Stored by VWO

Last updated

VWO uses cookies to run tests and to track user information. The cookies keep track of the variation a user has viewed and help to serve the same variation to the user consistently; track goals completed by a user; and determine whether a user is a part of a test.

VWO uses the following cookies to track users and test information:

  • _vis_opt_exp_EXPERIMENT_ID_goal_GOAL_ID: This cookie is generated when a goal is created.
  • _vis_opt_test_cookie: This is a temporary session cookie generated to detect if the cookies are enabled on the user browser or not.
  • _vis_opt_exp_EXPERIMENT_ID_combi: This cookie is generated when users reach a particular combination. This cookie ensures that users see the same variation that they saw on their previous visit to the page.
  • _vis_opt_exp_EXPERIMENT_ID_exclude: This cookie is generated when a user is excluded from a test.
  • _vis_opt_exp_EXPERIMENT_ID_split: This cookie is generated during a Split URL test.
  • _vis_opt_s: This cookie detects if the user is new or returning to a particular test.
  • _vis_opt_out: This cookie indicates that the visitor is not part of the test. This cookie is valid for 10 years.
  • EXPERIMENT ID refers to the ID of the test, and GOAL ID refers to the ID of the goal.
  • _vwo_uuid: This cookie generates a unique ID for every visitor and is used for the report segmentation feature in VWO. It also allows you to view data in a more refined manner. If you have a test running on multiple domains, you will notice test-specific UUID values.
  • In the _vis_opt_exp_EXPERIMENT_ID_combi cookie, the Control always has the value of 1, Variation #1 always has the value of 2, Variation #2 has the value of 3, and so on.

Change Cookie Duration

All the cookies except _vis_opt_test_cookie and _vis_opt_out expire in 100 days. To change the cookie duration, add the following JavaScript code snippet above the VWO tracking code on your webpage. 

<script type='text/javascript'>
_vis_opt_cookieDays = 1;
</script>
In this example, the cookie will last for a day only. To change the number of days, change the value from 1 to the required number of days. Note that after the cookies are created, the duration cannot be altered.

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