Google Ads

Overview

Google Ads is Google's advertising platform covering search ads, display ads, video ads, and remarketing campaigns. Its scripts appear on advertiser websites to measure conversions and build audience lists for retargeting.

What This Script Does

Google Ads deploys two primary script types on advertiser sites:

Conversion tracking (gtag.js with AW- config): Fires when a user completes a desired action (purchase, signup, form submission) after clicking a Google ad. The script reads the gclid (Google Click Identifier) parameter from the landing page URL and sets the _gcl_aw cookie to store it. When a conversion fires, the script sends the conversion event, value, and gclid back to Google Ads servers to attribute the conversion to the originating ad click and keyword.

Remarketing tag (gtag.js with DC- config or google_remarketing): Collects page visit data and adds visitors to audience lists in Google Ads. Sets the IDE cookie via doubleclick.net (third-party, 1-year expiry) and the _gcl_au cookie (first-party, 90-day expiry). These cookies enable Google to show targeted ads to your site's visitors as they browse other sites in the Google Display Network and YouTube.

Additional cookies include DSID, 1P_JAR, and NID set on google.com domains. Network requests fire to googleads.g.doubleclick.net, www.googleadservices.com, and google.com/pagead.

Enhanced Conversions: Some implementations collect hashed email addresses or phone numbers at conversion time and send them to Google for improved attribution matching.

Consent & Compliance

Google Ads falls squarely under the marketing consent category.

Under GDPR and ePrivacy, Google Ads scripts require explicit opt-in consent before loading. They set persistent cookies for cross-site tracking, transmit personal data (IP addresses, cookie identifiers, potentially hashed email addresses) to Google, and enable behavioral advertising across the web. There is no legitimate interest justification for advertising tracking.

Under CCPA, Google Ads remarketing constitutes "sharing" of personal information for cross-context behavioral advertising under the CPRA amendments. Users must be offered the right to opt out.

Google Consent Mode v2 allows Google Ads tags to load in a restricted mode when consent is denied, sending cookieless pings with ad_storage=denied and ad_user_data=denied. This preserves some conversion modeling capability without storing cookies, but the tags still fire network requests to Google. Whether this restricted mode requires consent is jurisdiction-dependent — some DPAs consider any data transmission to require consent.

Requirements for EEA targeting: Sites running Google Ads campaigns targeting EEA users must implement Google Consent Mode v2 and pass ad_storage, analytics_storage, ad_user_data, and ad_personalization signals. Without this, Google will not process EEA user data for measurement or personalization.

Should You Block This Without Consent?

Yes. Google Ads scripts exist solely for advertising measurement and retargeting. They set cross-site tracking cookies and share personal data with Google's advertising platform. Block all Google Ads scripts until the user grants marketing consent. If using Google Consent Mode v2, you may choose to load the tags in restricted mode without consent, but evaluate whether your jurisdiction treats the resulting data transmission as requiring consent.