Amplitude vs Google Analytics (GA4): which do you need?

This information is correct as of September 2026. Growth Method has made every attempt to ensure the accuracy and reliability of the information provided.

Most comparisons of Amplitude vs Google Analytics (or Amplitude vs GA4, if you use the shorthand) treat these tools as rivals. They mostly aren’t. Amplitude is a product analytics platform: events, funnels, retention, cohorts, experimentation. Google Analytics is a web and marketing analytics tool: sessions, channels, campaigns, conversions, wired into Google Ads. The real question is not which is better; it is which job you need done, and whether GA4’s limits have started to bite.

A disclosure before we start: we tend to recommend PostHog when teams consolidate their analytics, largely because we believe it has the strongest AI and MCP story of any provider. Growth Method itself is agnostic (customers can connect any analytics provider via MCP), including both of these.

Quick verdict: add Amplitude (or a rival) when you need to understand behaviour: where funnels leak, who retains, what to test next. Keep GA4 for what it is genuinely good at: free campaign and acquisition reporting inside the Google ecosystem. If you are trying to make GA4 answer product questions with explorations and workarounds, you have already outgrown it.

Amplitude vs Google Analytics (GA4) comparison

What GA4 is actually for

GA4 is the reporting layer of the Google advertising ecosystem, and judged on those terms it is unbeatable value: free at any traffic volume, natively linked to Google Ads for audiences and conversion import, and connected to Search Console. If your marketing runs on Google media, GA4 is not optional, and nothing here suggests removing it.

Its problems start when teams ask it to be a product analytics tool. Explorations sample once data volumes climb, cardinality limits collapse detailed reports into “(other)”, user-level retention analysis is shallow, and there is no session replay, no experimentation and no surveys. Simo Ahava, one of the most respected voices in the Google analytics community, put it plainly in his open letter about the platform:

Google Analytics 4 can be an extremely good tool in the digital analytics genre. Let’s just not pretend it’s there yet.

Simo Ahava, co-founder, Simmer

What Amplitude is actually for

Amplitude analytics was built for the questions GA4 fumbles: which behaviours predict retention, where activation funnels leak, which cohorts come back and why. Every plan now bundles session replay, feature and web experimentation, guides and surveys, and its AI features, priced on events (its old, hard-to-predict user-based pricing is gone). Cofounder Spenser Skates has been consistent about the founding aim since before the company listed:

Let’s build for the 99% of companies that don’t know how to use product data.

Spenser Skates, cofounder and CEO, Amplitude

What Amplitude is not is a media-buying tool. It imports ad spend, clicks and impressions from Google, Meta and LinkedIn, which is enough to put campaign cost next to product outcomes, but the Ads audience-sharing and conversion loops stay native to GA4.

Marketing analytics, product analytics, and the warehouse

This pairing is the clearest illustration of a distinction we push in every comparison: marketing analytics (channels, campaigns, spend, attribution) and product analytics (what users do once they arrive) are different jobs, and most teams need both done.

GA4 holds one unique card here: its free BigQuery export streams raw, unsampled event data into a warehouse you own, sidestepping every sampling and cardinality limit in the interface. Amplitude’s equivalent, warehouse-native Amplitude, is now a legacy feature closed to new customers. Our view is that every marketing team, regardless of size, should run a marketing data warehouse: GA4’s export makes BigQuery the natural start, with ad platform, CRM and product data joined alongside. Use GA4 and Amplitude as interfaces; own the data underneath. Route by job.

AI and MCP

Amplitude ships AI Agents that monitor dashboards, review replays and synthesise feedback, plus a hosted MCP server (we cover it in our Amplitude MCP guide) and AI Visibility for tracking how your brand appears in AI assistant answers. Google’s equivalent for GA4 is thinner: Gemini-powered insights in the interface, and an official MCP server that is experimental, self-hosted and read-only (see our GA4 MCP guide). For teams moving their analysis into AI assistants, Amplitude’s story is meaningfully ahead; GA4’s answer is, as ever, “export to BigQuery”.

Amplitude vs Google Analytics: which should you choose?

Choose Amplitude if you need to understand behaviour: funnels, retention, cohorts and experiments. Choose GA4 if your marketing runs on Google Ads and you need free campaign and acquisition reporting. Most B2B teams end up running both.

• Don’t frame it as either/or. Most B2B teams should run a free web analytics layer for media and campaigns, and a product analytics tool for behaviour.
• Let the questions decide. Write down the last ten questions your team asked of analytics. Channel and campaign questions point at GA4; behaviour and retention questions point at a product analytics tool.
• Set up the BigQuery export today regardless of anything else. It is free, it removes GA4’s sampling from the equation, and it future-proofs your marketing data warehouse.
• Shortlist the product analytics field. Compare Amplitude vs Mixpanel, PostHog vs Amplitude and PostHog vs Google Analytics before you commit.

Reviews

• G2: Amplitude vs Google Analytics

Final thoughts

When you weigh Amplitude analytics vs Google Analytics, the honest answer is both, for different jobs. GA4 is free, entrenched and genuinely good at Google-ecosystem marketing reporting; it is a weak product analytics tool wearing an event-based data model. Amplitude is a strong product analytics platform that cannot replace GA4’s Ads plumbing. Run the right tool for each job, export GA4 to BigQuery either way, and spend the time you save arguing about tools on the campaigns the data suggests.

About Growth Method

Choosing between Amplitude and GA4 settles where your data comes from. It does not settle what your team does with it, or whether the fix worked. Growth Method gives B2B marketing teams AI agents that run their campaigns: plan, launch and analyse, from live data, against one goal. Connect Amplitude, GA4 or anything with an MCP server, and the agents turn what your analytics show into prioritised campaigns, record the before-metrics at launch, then close the loop with data-driven attribution once they are live. Then repeat. Whichever tool wins, your team keeps a first-party record of what you tried, what moved and why.

Get started and put your analytics data to work on your next campaign.

Frequently asked questions

What is the difference between Amplitude and GA4?

GA4 is a free web and marketing analytics tool built around sessions, channels and Google Ads reporting. Amplitude is a product analytics platform built around events, funnels, retention and experimentation. GA4 tells you where your traffic came from; Amplitude tells you what people did next and whether they came back.

Should I use Amplitude or Google Analytics?

Most B2B teams should use both: GA4 for free campaign and acquisition reporting, especially if you buy Google Ads, and Amplitude once you need to see where funnels leak and who retains. If you can only pick one, look at the last ten questions your team asked of analytics. Channel and campaign questions point at GA4; behaviour and retention questions point at Amplitude.

Is Amplitude better than Google Analytics?

They do different jobs. GA4 is a free web and marketing analytics tool wired into Google Ads, built for campaign and acquisition reporting. Amplitude is a product analytics platform built for funnels, retention, cohorts and experimentation. Amplitude is far better at behavioural analysis; GA4 remains the default for media buying and Google ecosystem reporting.

Can Amplitude replace Google Analytics?

For behavioural analysis, yes; entirely, usually not. Amplitude imports ad spend, clicks and impressions from Google, Meta and LinkedIn, and covers events, funnels and attribution. But teams buying Google Ads typically keep GA4 for its native Ads linkage, audience sharing and conversion export, and run Amplitude alongside it for product analytics.

Is Amplitude free like Google Analytics?

Amplitude has a free plan with 2M events per month, 10K session replays and its AI features, which is enough for many small teams. GA4 is free at any traffic volume, with paid Google Analytics 360 for enterprises. At scale Amplitude becomes a paid contract, so GA4 stays the cheaper tool; the question is whether it answers your behavioural questions.

Does Google Analytics do product analytics?

Only superficially. GA4 moved to an event-based model and offers funnel and path explorations, but reports are sampled at scale, retention analysis is limited, there is no session replay, no experimentation (Google Optimize was discontinued in 2023), and no surveys. Teams that need real product analytics pair GA4 with a tool like Amplitude, Mixpanel or PostHog.

Can GA4 or Amplitude replace a marketing data warehouse?

No, but GA4 has the best on-ramp: its free BigQuery export streams raw, unsampled event data into a warehouse you own. Amplitude’s warehouse-native mode is now legacy and closed to new customers. Every marketing team, regardless of size, should run a marketing data warehouse alongside whichever analytics tools it uses.