Amplitude vs. Google Analytics 4: Which Is Right for Your Growth Team?

What each tool is actually built for

GA4 is a web analytics tool that evolved from a marketing attribution background. Its core strength is tracking traffic sources, measuring ad campaign performance, and reporting on sessions, users, and conversions at a aggregate level. Amplitude is a product analytics tool built from the ground up for behavioral analysis at the user level. It's designed to answer questions like: which users retained after 30 days, what did they do differently in week one, and which features correlate with expansion revenue? Different origin stories mean different strengths — and different answers.

Where Amplitude wins

Cohort analysis is where Amplitude is in a different league. You can define any behavioral cohort — 'users who triggered X event within 7 days of signup but did not reach Y milestone' — and instantly see how they retained, converted, and monetized compared to any other cohort. This kind of analysis takes minutes in Amplitude and is either impossible or requires BigQuery exports in GA4. Amplitude also wins on funnel analysis (any event sequence, not just predefined goals), user-level event streams, A/B testing integration, and the data model itself — Amplitude's event-property schema is far more flexible than GA4's rigid hit types.

Where GA4 wins

Cost is the obvious one — GA4 is free up to 10M hits/month, while Amplitude's paid plans start at meaningful numbers for scaling companies. GA4 also has native Google Ads integration that is genuinely hard to replicate: you get automatic conversion import, audience syncing, and attribution modeling that ties media spend directly to on-site behavior. If your team's primary analytics use case is media measurement and campaign optimization, GA4's Google ecosystem integration is a real advantage. GA4 also has a lower setup bar for teams without an event taxonomy already in place.

Can you run both?

Yes, and many growth teams do. A common setup: GA4 for marketing attribution and campaign reporting (it's free, keep it running), Amplitude for product analytics and retention analysis. The two tools don't overlap as much as they appear to — GA4 answers 'where did users come from and what did they do on the site,' Amplitude answers 'what did users do in the product and who came back.' The risk is data fragmentation: if your team is looking at different numbers in each tool, you need a clear source-of-truth policy before adding both.

The verdict for growth teams

If your primary growth lever is paid acquisition and your analytics maturity is early-stage, start with GA4. It's free, integrates natively with Google Ads, and covers the basics. If you're working on retention, activation, and product-led growth — or if you're running experiments and need cohort-level analysis — Amplitude is worth the investment. The question isn't which tool is better in the abstract; it's which tool answers the questions your growth team is actually asking.