Jetpack's built-in visitor analytics. It records page views, referring sites, search terms, and outbound link clicks, and also carries the shared visitor-tracking library used by Jetpack Instant Search and WooCommerce Analytics.
Service URL: automattic.com (opens in a new window)
tk_ai
Stores a randomly-generated anonymous visitor ID so Jetpack's Tracks analytics library can link tracking events to the same visitor.
Session in wp-admin; up to 5 years on the frontend
tk_qs
Queues analytics events for Jetpack's Tracks library so none are lost if the page closes before they can be sent.
30 minutes
tk_tc
Used once per page load to work out which cookie domain the Tracks library should use, then removed as soon as it's read back.
Session (deleted immediately after use)
tk_aip
Stores a list of anonymous visitor IDs so they can be merged into one identity once a visitor is recognized.
Up to 5 years
 
Craig V –
We used these on the Port Huron to Mackinac Race in 2024. We were in 6th and it helped us find and stay in the wind and get us back up to 2nd as the sun rised. We ended up 3rd because of it.