Enhanced Conversions is Google's answer to declining cookie reliability, using hashed first-party data instead. The feature improves conversion accuracy by sending hashed user identifiers, typically email addresses and phone numbers, from your website or CRM to Google, where they are matched against signed-in Google accounts. The hash algorithm is SHA-256, a one-way encryption that protects user privacy while enabling reliable matching. This approach recovers conversions that would otherwise be lost to browser restrictions like Safari's Intelligent Tracking Prevention and Firefox's Enhanced Tracking Protection, and it follows users across devices through persistent account data.
There are two flavors of Enhanced Conversions, and the difference lies in timing. Enhanced Conversions for Web sends hashed data at the moment of conversion on the website, typically via Google Tag Manager or the gtag.js library. Enhanced Conversions for Leads uploads hashed data later, often through a CRM like HubSpot, when a lead progresses in the funnel or closes a deal. This makes it a form of offline conversion matching that relies less heavily on the GCLID and more on the persistent identifiers themselves. Compared with classic Offline Conversion Import, which depends heavily on the GCLID alone, Enhanced Conversions for Leads can combine the GCLID with hashed email and phone data for substantially better match rates.
With privacy regulations tightening, Consent Mode has become a critical layer of the tracking stack. Consent Mode adjusts how Google tags behave based on the user's consent choices. In its v2 implementation, the Basic mode blocks tags entirely until consent is granted, while the Advanced mode loads tags immediately and sends anonymized pings without cookies until consent arrives, allowing Google to model conversions that were never directly observed. Some advertisers also adopt Server-Side Tagging, where data flows from the web server directly to Google's servers rather than from the user's browser, improving data control, security, and resilience to ad blockers. HubSpot's role in this privacy-first world is to send hashed identifiers along with optimization events, ensuring conversion data continues to flow back to Google even without third-party cookies.