Google Analytics Cookies
Name Description Used for Expiration
__utma Written to the browser upon the first visit to your website from that browse Used for unique visitors 2 years
__utmb Establishes and continues a user session to your website. For visitor sessions 30 minutes
__utmc No longer used
__utmz Stores the type of referral used by the visitor to reach your website Used to calculate sources of traffic 6 months
__utmv Passes the information provided via the _SetCustomVar() method 2 years
__utmx Set when the website optimizer tracking code installed in your website Used by website optimizer 2 years