What attribution model does google ads use?

What attribution model does google ads use?Google Ads uses last-click attribution by default, meaning it assigns 100% credit to the final ad click before conversion. You can switch to data-driven, first-click, linear, time-decay, or position-based models in the attribution settings, but most accounts stick with last-click or data-driven if they have enough conversion volume.AnswerGoogle Ads defaults to last-click attribution, which gives full credit to the last Google Ads click before someone converts. If a user clicks your ad, browses your site, leaves, then comes back via organic search and converts, Google Ads gets 100% credit under last-click because it ignores non-Google-Ads touchpoints in its own reporting.You can change this in Tools & Settings > Measurement > Attribution. Your options are data-driven (requires 3,000 ad interactions and 300 conversions in 30 days), first-click, linear, time-decay, and position-based. Data-driven uses machine learning to distribute credit based on actual conversion patterns in your account. Linear splits credit equally across all clicks. Time-decay gives more weight to recent clicks. Position-based assigns 40% to first click, 40% to last, and 20% split among middle clicks.Most accounts under 500 conversions per month stay on last-click because they don't qualify for data-driven or don't have enough cross-channel data to make other models meaningful. If you're running Shopping, Search, Display, and YouTube together, switching to data-driven often reveals that upper-funnel campaigns contribute more than last-click suggests, which changes your ROAS targets.One common mistake: Google Ads attribution only sees Google Ads clicks. It doesn't attribute Meta ads, organic social, email, or direct traffic unless you layer in Google Analytics 4 and use its attribution reports alongside Ads data. GA4 offers similar models but includes all traffic sources, so the two platforms will show different conversion counts and credit distribution for the same campaign.At Ottawa SEO, we typically leave Smart Bidding campaigns on last-click until we have 90 days of stable data, then test data-driven if volume supports it. For lead-gen clients with long sales cycles, we cross-reference GA4's position-based model to justify keeping upper-funnel keyword groups that last-click undervalues. Attribution models don't change what actually happened, they just shift how you allocate budget and interpret performance.