GBRAID is a URL parameter that Google Ads appends to ad clicks from Apple devices running iOS 14 or later, where the usual Google Click Identifier (GCLID) cannot be used. It exists because of Apple's App Tracking Transparency (ATT) rules. A GCLID is unique to one click, and through it to one person's path from ad to purchase. A GBRAID value is not unique: Google describes it as closer to a campaign ID than to a click ID, according to Google documentation summarised by PPC Land. That trade lets Google keep crediting conversions to campaigns on iPhones without following an individual across apps and websites owned by other companies. Its sibling, WBRAID, covers the opposite direction of travel.

Why Google needed a new identifier

Apple's ATT framework took effect on April 26, 2021, with iOS 14.5. It requires apps to ask permission before tracking a user across other companies' apps and websites, and most users decline. Google's response, according to its Google Ads help page "Updates to iOS 14 campaign measurement", was to stop sending the GCLID "for iOS 14 traffic coming from ads on a handful of Google apps". Its Analytics help page puts it more broadly: the GCLID "is no longer used without user consent in iOS14+."

That decision opened a measurement gap. A click on an ad inside the Google Search app or YouTube on an iPhone, leading to a purchase on a retailer's site or in a retailer's app, crosses company boundaries. Without a click identifier, Google Ads could not see the sale. Google introduced two parameters to close the gap. WBRAID arrived first: "In March 2021, we introduced a new URL parameter", the Google Ads help page says. GBRAID followed in May 2021, added to landing page URLs when auto-tagging is enabled "for all iOS14.5+ clicks."

Google has not published an official expansion of either acronym.

Which direction is which

Google's documentation and its own trade coverage do not describe the split in the same way. According to Google's Analytics help page, "For web to app measurement, the parameter is known as GBRAID, and for app to web measurement, it's known as WBRAID." The Google Ads help page ties GBRAID to app deep-link conversions and WBRAID to website conversions from ads in Google apps. Yet when GA4 first added support, PPC Land reported Google describing GBRAID as app-to-app and WBRAID as app-to-web, and a 2025 article on iOS 26 repeated the app-to-app label.

Practice blurs the line further. Advertisers routinely see gbraid on ordinary web landing pages from iOS traffic, often together with a gclid. Google lists GBRAID as applicable to Search, Shopping, Display and Performance Max campaigns.

How the parameter travels

The mechanics follow the GCLID pattern. With auto-tagging enabled, a click lands as something like example.com/?gbraid=0AAAAA.... The Google tag, Google Tag Manager or analytics.js with a linked Google Ads account then "will set a new first-party cookie on your domains by default", according to Google, storing the value so that a later conversion on the same site can be reported against it. Sites that reject unknown query strings have to allow gbraid= explicitly, Google warns, or the click arrives with nothing attached.

What happens at Google's end is less documented. Because the value is shared across many clicks, a conversion reported with it cannot be tied to one user. Google pairs these observations with conversion modeling, its statistical estimate of conversions it cannot directly observe. GA4 reports affected traffic as google / cpc and "will use modeled conversions", according to the Analytics help page, with campaign-level dimensions sometimes showing as "(not set)".

Offline conversions and the API

The parameter matters most outside the browser. Businesses that close sales by phone, in a showroom or through a sales team store the click identifier in a customer relationship management (CRM) system and upload the sale later through Google's offline conversion import. The Google Ads API's ClickConversion object accepts gclid, gbraid and wbraid fields.

Braid uploads come with restrictions that GCLID uploads do not:

  • Custom variables and cart data are not supported. Google's API troubleshooting page says a conversion carrying gbraid or wbraid without a gclid fails with FieldError.VALUE_MUST_BE_UNSET if custom_variables or cart_data is set.
  • Enhanced conversions for web, which match hashed customer data to a conversion after the fact, do not work for conversions where "gbraid or wbraid was populated instead of gclid", according to the same page.
  • Both braids at once are rejected, with the error ConversionUploadError.GBRAID_WBRAID_BOTH_SET.
  • One-per-click counting, which records at most one conversion per click and is common in lead generation, has repeatedly been reported as incompatible with braid uploads in Google's developer forum and by vendors such as Able CDP. Google's current troubleshooting page does not list the restriction.

The rule on combining GBRAID with a GCLID changed in 2025. Until then, a conversion carrying both failed with VALUE_MUST_BE_UNSET. On July 22, 2025, Ben Karl announced for the Google Ads API team that, from October 3, 2025, ClickConversion messages may set both gclid and gbraid.

Who handles it

On the buy side, Google generates the value and the advertiser or agency switches on auto-tagging. Capture is the advertiser's job. Every system that stores click identifiers - a CRM form field, a server-side tag container, a call tracking platform - has to store gbraid and wbraid as well as gclid, or iOS conversions drop out of offline uploads. Support among mobile measurement partners is uneven: Google's own help page notes that Airbridge's server-to-server API "doesn't support gbraid", while Kochava's example passes both identifiers.

There is no sell-side role in the programmatic sense. Publishers neither see nor trade on the value; it travels from a Google ad surface to the advertiser's property.

Why it matters for marketers

The stakes are counts and bids. If forms, redirects or a CRM keep only gclid, conversions from braid-tagged clicks never reach Google Ads. Automated bidding then sees fewer iOS conversions than occurred and bids accordingly.

Redirects are a common failure point. On July 30, 2026, Google added a Google Analytics diagnostic, "Campaign data accuracy is affected by missing URL parameters", that fires when GBRAID or gad_ parameters are missing from URLs that carry a GCLID. Stripped traffic shows up as "(not set)" or organic. The same coverage noted that the aggregate identifiers matter most when a visitor denies ad_user_data consent.

Safari is the other pressure. Apple's Link Tracking Protection, announced in June 2023, strips known click identifiers such as gclid from links in Mail, Messages and Private Browsing. Testing before Safari 26 shipped found that private browsing removed gclid but preserved gbraid, while Frederik Boysen of ProfitMetrics reported that gclid was "NOT stripped by default" in regular browsing. In April 2026, analytics consultant Luc Nugteren estimated that Safari's default fingerprinting protection strips the GCLID in about 20% of Safari sessions, and said "both GBRAID and WBRAID parameters are never removed" by that mechanism. Where gclid disappears, the braid value is often the only link left between click and sale.

Limitations and criticism

Precision is lower by design. A non-unique value cannot support per-click joins. Lead scoring, user-level attribution and CRM-to-ad reconciliation all weaken, and PPC Land's iOS 26 coverage noted that GBRAID "cannot support remarketing or audience building."

Feature gaps persist. The exclusions on custom variables, cart data and enhanced conversions for web mean that iOS conversions reach Google with less information than the same conversions on Android.

Reliance on modeling. Because braid-based reporting leans on modeled conversions, part of what advertisers see for iOS is estimated rather than counted, and Google publishes little about how values are grouped or how the models are calibrated.

Inconsistent documentation. Google's own pages and its reporting over time disagree about whether GBRAID is web-to-app or app-to-app, which complicates implementation guides and vendor support.

Consent is still required in Europe. A value stored in a first-party cookie and read back still falls under the ePrivacy Directive's consent rule, whatever Google does with it server-side.

  • GCLID. The Google Click Identifier, a unique per-click value appended by auto-tagging. GBRAID is its non-unique counterpart for iOS 14+ traffic; since October 3, 2025, both can travel on one API upload.
  • WBRAID. The sibling parameter for app-to-web conversions, introduced in March 2021. It cannot be uploaded together with GBRAID.
  • gad_source and gad_campaignid. Newer Google Ads parameters that describe the source and campaign of a click rather than identify it. All conversions from one campaign share the same gad_campaignid value.
  • SKAdNetwork and AdAttributionKit. Apple's own frameworks for attributing app installs, which report to ad networks with delays and limited data. They run inside Apple's systems; GBRAID runs inside Google's.

Recent developments

The identifier has grown more important, not less, since 2021. The October 2025 API change removed a long-standing obstacle to uploading iOS conversions that carried both identifiers. Safari 26, released in September 2025, and its fingerprinting protections made the GCLID less reliable on Apple devices while leaving braid values intact, according to testers cited by PPC Land. In April 2026 Nugteren described a workaround, appending the GCLID under a renamed parameter and rebuilding the cookie, though it works only for Google Ads. The July 30, 2026 GA4 diagnostic made missing GBRAID values visible inside Google's own tools for the first time. As of November 2026, Google documents GBRAID and WBRAID as standard auto-tagging parameters, accepted by the Google tag, GA4 and the offline import.

Timeline

  • March 2021 - Google introduces the WBRAID URL parameter.
  • April 26, 2021 - Apple's App Tracking Transparency takes effect with iOS 14.5.
  • May 2021 - Google introduces the GBRAID URL parameter for iOS 14.5+ clicks.
  • March 7, 2022 - GA4 updates iOS 14+ campaign measurement to use GBRAID and WBRAID.
  • June 2023 - Apple announces Link Tracking Protection, stripping known click identifiers in Mail, Messages and Private Browsing.
  • July 22, 2025 - Google announces that the Google Ads API will accept gclid and gbraid on one conversion.
  • September 2025 - Safari 26 ships with Advanced Fingerprinting Protection enabled by default.
  • October 3, 2025 - Dual gclid and gbraid uploads take effect in the Google Ads API.
  • April 2026 - Luc Nugteren estimates Safari strips the GCLID in about 20% of sessions, leaving braid values intact.
  • July 30, 2026 - Google Analytics adds a diagnostic for GBRAID and gad_ parameters missing from GCLID URLs.

Summary

Who: Google created GBRAID and generates it through Google Ads auto-tagging. Advertisers, agencies, CRM, analytics and measurement vendors must capture and pass it on. Apple's ATT rules are the reason it exists.

What: A non-unique URL parameter that lets Google Ads credit conversions from iOS 14+ clicks to campaigns without a per-user click identifier, supported by conversion modeling. WBRAID is its app-to-web sibling.

When: Introduced in May 2021, weeks after ATT took effect on April 26, 2021. Accepted alongside the GCLID in the Google Ads API from October 3, 2025, and monitored by a GA4 diagnostic from July 30, 2026.

Where: On landing page URLs from Google ads clicked on iOS devices, in first-party cookies set by the Google tag, in GA4 reporting and in offline conversion uploads.

Why: To keep conversion data reaching Google's reporting and bidding on iPhones, where a unique click identifier conflicts with Apple's tracking rules and is increasingly stripped by Safari.