GA4 Killed First-Click Attribution in November 2023. Most Teams Never Noticed.

Google Analytics 4 offers three attribution models today: data-driven, paid and organic last click, and Google paid channels last click. First click, linear, time decay, and position-based were removed in November 2023, and most teams never noticed, because most of their reports never used the attribution model at all.

The three models that remain

Data-driven attribution is the default. It uses machine learning to spread credit across the touchpoints in a path, weighted by how much each one seemed to matter based on your property's own converting and non-converting paths. Paid and organic last click gives all the credit to the last channel the buyer clicked through from before the key event, ignoring direct visits. Google paid channels last click gives all the credit to the last Google Ads click, and falls back to paid and organic last click when there was no Google Ads click in the path.

The removed models are gone from the interface, not just deprecated. Google's attribution documentation states plainly that first click, linear, time decay, and position-based models are no longer available as of November 2023, and Google Ads completed the same removal that September. A guide written before then that tells you to compare first-click and last-click is describing a product that no longer exists.

The lookback window sets how far back a touchpoint can earn credit. The default is 90 days for most key events, with 30 or 60 also possible, and 30 days for acquisition key events, with 7 also possible. The window only applies from the day you change it. It does not rewrite history, which is the detail teams miss when they change it mid-quarter and wonder why the past did not move.

The catch: most reports never use the model

GA4 attributes traffic at three scopes, and only one of them uses your reporting attribution model. User scope shows the channel that first acquired the user, and it is fixed. Session scope shows the channel that started each session, and it is fixed at last non-direct click. Only event scope, the channels that contributed to a key event, uses the reporting model, and it only applies when you view key events with event-scoped dimensions. Related reading: Last Click Gives One Channel the Sale and Lies About the Rest.

That means the Traffic acquisition report, the one most teams look at every morning, never shows data-driven attribution. It is session-scoped, so it shows last non-direct click regardless of your model setting. The same purchase can sit under three different channels in three different reports, by design, and all three can be correct. A team that changes the model setting and sees no change in Traffic acquisition has not found a bug. It has found a scope.

The place to see the model work is Advertising, then Attribution, then Attribution Models, where you can compare how conversions and revenue shift between data-driven and last-click. Or build an exploration with event-scoped dimensions like Source, Medium, and Campaign. If your model comparison lives anywhere else, you are comparing scopes, not models.

Why GA4 disagrees with Google Ads

The two products use different rules, and the disagreement is documented. Direct visits get no credit in any GA4 model unless the entire path was direct, which quietly reallocates credit away from direct traffic. GA4 data can keep changing for up to 12 days as late-arriving events settle. And Google Ads credits on its own click and view windows, not GA4's. A purchase that GA4 credits to organic search and Google Ads credits to a paid click is not an error in either tool. It is two different attribution rules applied to the same path.

The practical rule is to keep data-driven as the default if you have steady sales every week and mostly want to see which channels start and help sales, not only finish them. Switch to last click only when volume is so low that the data-driven model has too little to learn from, or when you need to explain every credit decision to stakeholders and the model's opacity is a bigger problem than its accuracy. And remember that a model setting moves credit between the purchases GA4 saw. It cannot add the ones it missed. More on this: The Discount Code That Stole Credit From Every Other Channel.

Frequently asked questions

Should I switch from data-driven to last click?

Only if your volume is too low for the model to learn from, or if you need to explain every credit decision and the model's opacity is a problem. For most stores with steady sales, keep data-driven.

Why does GA4 disagree with Google Ads?

Different models, different lookback windows, and different handling of direct visits. GA4 also keeps settling data for up to 12 days. The disagreement is documented, not a bug.

Where do I change the attribution model?

Admin, then Attribution settings. The change applies going forward only, and it only affects key events viewed with event-scoped dimensions.

Why didn't my Traffic acquisition report change when I changed the model?

That report is session-scoped and always uses last non-direct click. The reporting model only applies to event-scoped key event reporting.