Google Click ID (GCLID) is a URL parameter passed with ad clicks. This parameter identifies the campaign along with other attributes of the click associated with the ad for ad tracking and campaign attribution.
In Google Ads, this is activated by turning on the auto-tagging setting. It’s required for Google Ads website conversion tracking. You can use the GCLID parameter to link data between Google Ads and Google Analytics. It can also be used in conjunction with features like offline conversion tracking.
Learn more about how to Set up offline conversions using Google Click ID (GCLID).
