Most Google advertisers understand that Google click IDs (known as GCLIDs) can help power Google Ad smart bidding campaigns when they are captured and uploaded back to Google.

However, GCLIDs have recently started “disappearing” in some cases, and/or being replaced by GBRAIDs and WBRAIDs in certain instances. Why is this happening?

It all comes down to changes Google has made in the wake of Apple’s iOS14.5 software update.

NOTE: Apple has done it again with IOS 17. To read about why GBRAIDS and GCLIDS are doing to "disappear", click here

In summary, if a click is coming from an iOS device, and the user has opted out of tracking, you will see either a GBRAID or WBRAID, depending on criteria you can read about below.

If your Google Ad click is coming from a NON-iOS device, you will still see GCLIDs and be able to optimize them as normal.

Here are all of Google’s resources on this change:

Bidding considerations for impacted campaigns
Campaigns using Smart Bidding will continue to set bids based on the most accurate measurement available. However, we recommend that you prepare for the above changes by closely monitoring the performance and delivery of all campaigns serving on iOS traffic and, if necessary, make adjustments to budgets and Smart Bidding CPA or ROAS targets to help you achieve your goals. For example: If you would like to increase spend, you can raise CPA targets or lower ROAS targets as needed.

When Apple’s ATT policies take effect, we will no longer send the Google click identifier (GCLID) for ads on iOS 14 traffic coming from impacted Google apps. This new ATT compliant parameter, known as “wbraid”,replaces gclid on most iOS surfaces. Advertisers should ensure that the destination websites in their advertising campaigns can receive an additional passed URL parameter and that any web attribution systems they may have can support this parameter, when needed. On non-iOS surfaces, “gclid” will continue to serve as the primary mechanism by which we attribute conversions. Please note that search is not affected by this change, and will continue to use gclid.

Q: What should my advertiser do to ensure they are prepared?
A: As a best practice, we recommend the advertiser implement One Google Tag (OGT) (gTag.js and/or Google Tag Manager).
In addition, a small percentage of advertisers may need to ensure their site is able to accept arbitrary URL parameters by following the directions here ->

Q: How does this new parameter work?
A: Similar to GCLID, this new parameter is dropped in a 1st party cookie set by A Google Tag (including gTag.js, gtm.js, and analytics.js linked to an ads account) when a user lands on a page after clicking on an ad. This parameter helps attribute conversions back to ad campaigns but does not uniquely identify the user.

Q: Why is this new parameter ATT compliant but gclid is not?
A: This new parameter uses techniques that ensure it cannot be tied back to any one individual user. wbraid uses aggregation techniques to ensure ATT compliance. We are exploring additional techniques like deidentification, in line with Apple’s ATT policies.

Q: What is the visible impact of this change?
A: This is a backend change that advertisers will not see in the Google Ads UI (front-end). The new parameter will be dropped in a 1st party cookie by default and this parameter will be used to pass conversions to your Google measurement solutions in an ATT compliant manner. As always, advertisers can opt out of 1st party measurement all together which will disable use of GCLID as well as this new parameter. Advertisers may see this new parameter present in some URLs that originate on iOS traffic

Q: What is the difference between the “gbraid” and “wbraid” parameters?
A: Both parameters function similarly, in that they are added to the URL (in place of historical identifiers) to measure when the ATT prompt is not accepted. Both parameters also use aggregation techniques to attribute conversions. However, notable differences exist as well:

  Gbraid Wbraid
Where is it used? App measurement (deep linked campaigns) Web measurement
What campaign types? Search/Shopping YouTube/Display/Discovery
Example? Web→ App. Joe clicks on a web ad for shoes, which takes him to a popular shoe app. In the app, Joe purchases a pair of shoes
App → Web. An ad for shoes runs in the YouTube app. Joe clicks on the ad and it takes him to the shoe brand’s website. On the site Joe purchases a pair of shoes
Reporting Granularity No change to reporting granularity No change to reporting granularity

Q: Will advertisers see any change in conversion volume?
A: Advertisers may see a drop in reported conversions if they do not configure their servers to receive this parameter as they may break web attribution systems.

Q: What formats does this impact?
A: This new parameter is relevant to the following formats on iOS14+ only: YouTube, Discovery, Google Maps, Gmail, AFS iOS app partners, 3rd party apps. Search is not impacted. subject to this change.

Q: What products are subject to this change?
A: This new parameter is relevant to the following products on iOS14+: Google Ads Conversion Tracking, Offline conversion tracking (OCFS, OCI), Google Analytics, Click Performance Report (CPR), DS Cost Reporting. Technically, it works through the global site tag (gTag.js or Google Tag Manager)

Q: What techniques does this new parameter use that makes it resilient on iOS 14?
A: This new parameter will use a variety of techniques to ensure measurement observability and campaign attribution on iOS surfaces:
  • Aggregation techniques that only use the parameter when a group of users complete a similar conversion path e.g; campaign ID
  • De-identification techniques that ensure cross-site behavior cannot be tied back to a user’s identity
Q: Is this an alternative to conversion modeling?
A: No. This new parameter works in tandem with conversion models to provide the most robust measurement on iOS surfaces. For example, we will continue to use conversion modeling to surface conversions that are not observable due to Apple’s ITP (Intelligent Tracking Prevention)

Q: Is GCLID going away?
A: No. Gclid will continue to serve as the event identifier used in surfaces that are not impacted by ATT for web measurement, such as events in browsers and non-iOS surfaces. This new parameter will only be used when gclid is not available on impacted iOS surfaces. Again, when Apple’s ATT policies take effect, we will no longer send the Google click identifier (GCLID) for ads on iOS 14 traffic coming from a handful of Google apps.