Consent Mode and how GA4 fills missing data with behavioral modeling and modeled conversions

Google Consent Mode is a system that allows GA4 tags to fire even when users reject cookie tracking, sending limited 'cookieless pings' that are combined with behavioral patterns from consenting users to model estimated conversions and sessions. In advanced mode, GA4 mixes real observed data with machine-learning predictions without distinguishing between them in reports, making it impossible to know how much of your dashboard reflects actual user behavior. This creates a legal gray area since data is still sent to Google servers before anonymization, and small sites often can't meet the minimum thresholds required to activate modeling at all. Plausible is presented as a cookieless, privacy-first alternative that collects only real event data without requiring consent banners, behavioral modeling, GTM configuration, or BigQuery exports.