_vis_opt_test_cookie: This is a session (temporary) cookie generated to detect if the cookies are enabled or not on the browser of the user.
_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 test.
_vis_opt_exp_EXPERIMENT_ID_split: Thie 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. It is valid for 10 years.
EXPERIMENT ID refers to the ID of the Test and the GOAL ID refers to the ID of the goal.
In the 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 expire in 100 days.