The Page Click ID is a 30-character ID that the command AnyTrack('atclid') returns. It has three parts: the 12-character Property ID, the 14-character Client ID, and a 4-character time code for the current minute. People often call it the atclid, but atclid is a name, not one value. See atclid.
How the time code works
Section titled “How the time code works”The 4 time characters encode the current minute in base 62. This is an encoding, not encryption: AnyTrack decodes it to read the minute. The Tracking Tag computes the value each time something asks for it and does not store it. Two requests in the same minute return the same Page Click ID. The value changes when the minute changes or when the Client ID changes.
How the Page Click ID relates to the Click ID
Section titled “How the Page Click ID relates to the Click ID”A Click ID also starts with the Property ID and the Client ID. It then adds an 8-character event ID for one tracked event, such as the click on one link or the submit of one form. The event ID holds 4 time characters and 4 random characters. The first 30 characters of a Click ID equal the Page Click ID only when both are made in the same minute. The last 4 characters of a Click ID are random.
How AnyTrack matches a Page Click ID
Section titled “How AnyTrack matches a Page Click ID”A Page Click ID does not point to one exact event. AnyTrack finds the visitor from the Client ID and matches the latest event of that visitor, up to 2 minutes after the minute in the value. A Click ID matches one exact event. See Server-Side Client ID for the matching rules by length.
Notes on the Page Click ID
Section titled “Notes on the Page Click ID”PageView is the only standard event that does not generate a Click ID by default. In Shopify, the Page Click ID is carried into the order in the note_attributes.__atclid and line-item properties._atclid fields, so the server-side order matches back to the browser session.
Frequently asked questions
FAQ was last reviewed on 2026-11-08