VWO uses the following cookies to track users and campaign information:
- _vis_opt_exp_EXPERIMENT_ID_goal_GOAL_ID: This cookie is generated when a goal is made.
_vis_opt_test_cookie: This is a session (temporary) cookie generated to detect if the cookies are enabled on the browser of the user or not.
- _vis_opt_exp_EXPERIMENT_ID_combi: This cookie is generated when users reach a particular combination. This makes sure that users see the same variation that they earlier saw when they visited the page.
- _vis_opt_exp_EXPERIMENT_ID_exclude: This cookie is generated when a user has been excluded from a campaign.
- _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 campaign.
- _vis_opt_out: This cookie indicates that the visitor is not part of the campaign. It is valid for 10 years.
- EXPERIMENT ID refers to the ID of the campaign and the 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, and it also allows you to view data in a more refined manner. If you have the campaign running on multiple domains, you will notice campaign 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.
Note: All the cookies except the _vis_opt_test_cookie and _vis_opt_out expire in 100 days.