Google Click ID (GCLID) will now be generated at impression-time

Currently, if you turn on auto-tagging, when a user clicks on your ad, a unique Google Click ID (GCLID) will be generated that you can use to track offline conversions using UploadConversion. If a user clicks on your ad several times, you will get multiple GCLIDs, one for each click. Click Performance Report shows click details by returning one row for each click, which is equivalent to one GCLID.

In Q4 2016, we will change the timing of GCLID generation to impression time (or when your ad is shown) instead. As a result, if a user clicks on a particular ad impression multiple times, those clicks will be associated with only one GCLID. Consequently, landing page visits for the exact same impression will share the same GCLID value. This change opens the door for future improvements to user experience with Google ads.

To report the number of clicks associated with a GCLID, we are adding a new report field, Clicks, to Click Performance Report before this change. If your ads are normally clicked many times per impression, you will seefewer rows returned by Click Performance Report. For click-time GCLIDs, Clicks will always be returned as 1.

What you should do

  • Ensure that your application is aware of multiple clicks to your landing pages with the same GCLID.
  • Do not make any assumption that a GCLID is unique per click.
  • If you use the Click Performance Report, be aware that you may get fewer data rows than before.


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