PostHog vs Google Analytics: Which Fits Your Team?

Olamide Sule, founder of Dolphin Analytics: a digital analytics expert based in London delivering solutions for agency and in-house clients.

“PostHog or Google Analytics” is a question we get from SaaS and B2B teams almost every month, and it usually starts from a false choice: that the two do the same job and you have to pick one. They don’t. GA4 is web analytics and PostHog is product analytics, so they answer different questions. We picked PostHog alongside GA4 for our own site, and we set the same pairing up for clients, so this is the head-to-head we’d actually give you, not a feature-count scorecard.

Product and pricing details link to each vendor’s own pages. These tiers move, so verify current pricing before you commit.

PostHog vs Google Analytics: what’s the real difference?

PostHog is product analytics and GA4 is web analytics, so they answer different questions rather than compete for the same job. PostHog measures behaviour inside a product or app: which features get used, where people drop off in a flow, and what a recorded session shows when something breaks. GA4 measures traffic, campaigns and conversions: where visitors came from and whether marketing worked.

That split is the whole decision. A product team working out why users abandon onboarding needs PostHog. A marketing team proving which campaigns drive signups needs GA4. Both tools record events, so on the surface they look interchangeable, but they are tuned for different owners asking different questions. The wrong pick wastes months, however good the dashboard looks in a demo.

PostHog vs GA4: head to head

Here is how the two line up on the things that actually decide the choice.

	PostHog	GA4
What it measures	In-product events, funnels, cohorts, retention	Traffic, channels, campaigns, conversions
Best fit	Product and engineering-led teams	Marketing teams, especially Google Ads-led
Bundled tools	Session replay, feature flags, A/B tests, surveys	Reporting only; no replay or flags
Data capture	Autocapture plus custom events	Enhanced measurement plus custom events
Pricing	Usage-based; generous free monthly allowance	Free; paid GA360 tier for scale
Hosting and data location	Cloud (US or EU), or self-hosted open source	Google-hosted only
Google Ads integration	None native	Native, the core reason to run GA4
Setup effort	Medium; SDK plus an event plan	Low to medium

Product details link to each vendor’s pages; verify current tiers before you buy.

When GA4 wins

Pick GA4 when the questions are about marketing. It is free for the vast majority of sites, and its integration with Google Ads is the strongest single reason to run it: conversion data flows straight back into campaign optimisation without a separate connector. Nothing in PostHog replaces that link to paid search reporting.

The limits show up past marketing reporting. Data retention caps user- and event-level detail at 14 months, which only affects Explorations and funnel reports, not standard aggregated reports. Ad-hoc queries can sample once a single query crosses 10 million events, and the fix for both limits is exporting raw data to BigQuery. For marketing and acquisition reporting, though, GA4 is hard to beat on price and on how well it plugs into the rest of the Google stack.

When PostHog wins

Pick PostHog when the questions are about the product. It bundles product analytics, session replay, feature flags, surveys and experiments into one platform, so a team can watch a user struggle through a broken flow, ship a fix behind a feature flag, and measure the funnel change without stitching four tools together. GA4 does none of that.

PostHog’s autocapture is the other draw: it records front-end interactions automatically, so you can answer questions retroactively without having instrumented every click in advance. That convenience has a cost. Autocapture generates a lot of events, event volume drives the bill, and the data still needs a clear naming plan before funnels and cohorts stay trustworthy. The tool is only as good as the event model behind it, the same rule that applies to GA4 and every product analytics platform.

Pricing and event model: how each one charges

GA4 is free at the volumes most sites ever reach, with a paid GA360 tier for enterprises that need higher limits, less sampling and service-level agreements. You pay for scale and support, not for different features.

PostHog charges on usage, metered per product: analytics events, session recordings, feature flag requests and survey responses each have their own free monthly allowance before usage pricing kicks in. The model rewards small teams (the free tier covers a lot of early traffic) and scales with you, but it also means a busy consumer app can run up a real bill from autocapture alone. Budget by expected event volume, not by seat count, and turn off capture on high-traffic, low-value events early.

The practical contrast: GA4’s cost is predictable because it is usually zero, while PostHog’s cost tracks how much you measure. For a marketing site, GA4 is free and PostHog’s free tier is plenty. For a high-traffic logged-in product, PostHog’s bill becomes a line item worth managing.

Privacy and data ownership: where the data lives

PostHog gives you more control over data location than GA4 does. It offers a US or EU cloud and an open-source build you can self-host, so analytics data can stay on infrastructure you choose, which matters for teams with strict data-residency rules. GA4 is Google-hosted only, and while Google now relies on the EU-US Data Privacy Framework for transatlantic data transfers (European Commission adequacy decision, 10 July 2023), you cannot move where the data sits.

Neither tool removes the need for a consent banner in the UK and EU. Both set cookies and process behavioural data, so consent management applies either way. Self-hosting PostHog changes where the data lives; it does not, on its own, make analytics exempt from consent. If your setup is losing a chunk of UK and EU traffic to a misconfigured consent banner, that gap follows you to whichever tool you choose, which is a tracking problem, not a platform one.

What we learned running both

Running GA4 and PostHog side by side, the division of labour settles quickly: GA4 owns acquisition and marketing reporting, PostHog owns product behaviour. The friction is never “which tool is better.” It is keeping the two event models from drifting apart, so a “signup” in GA4 means the same thing as a “signup” in PostHog. When those definitions diverge, the two dashboards disagree, and someone spends a morning working out which number to trust.

That reconciliation work is the real cost of running both, and it is where most teams underestimate the setup. A shared event naming plan, agreed before either tool goes live, saves that morning every week. For the wider category view, our digital analytics tools comparison covers six platforms including PostHog, and our GA4 versus Mixpanel comparison walks the same web-versus-product split with a different product tool.

Which one should you actually pick?

For most marketing teams, GA4 is the default: free, and unbeatable for Google Ads reporting. Add PostHog once the questions turn to in-product behaviour that GA4’s event model handles clumsily, or when you want session replay and feature flags in the same tool as your analytics. Reserve the “PostHog only” setup for small products with no paid search spend, where one tool is worth the trade-off.

Your situation	Pick
Prove which marketing channels and campaigns work	GA4
Understand in-product behaviour, funnels and retention	PostHog
Watch session replays and ship behind feature flags	PostHog
Run Google Ads and need conversion reporting	GA4
Keep analytics data in the EU or self-hosted	PostHog
Small product, no paid search, want one tool	PostHog alone
SaaS team measuring both marketing and product	GA4 for marketing, PostHog for the product

Most product teams run two tools: GA4 for marketing, PostHog for what happens inside the product. One is not a replacement for the other, and the strongest setups treat them as a pair with a shared event plan.

Why the tool matters less than the tracking underneath it

Choosing the platform is the easy part. Whether it gives you numbers you can trust comes down to implementation: whether events fire consistently, whether consent is set up so you’re not silently losing UK and EU traffic, and whether the figures match what actually happened in the business. A perfectly chosen tool sitting on a broken tag setup produces confident-looking, wrong data, which is worse than no data at all.

Duplicate events from an old migration, a conversion that stopped firing after a checkout redesign, a signup that PostHog counts and GA4 misses: those faults break the numbers on either tool just the same. We do this implementation work for clients most weeks, and every figure in the reports we build is machine-checked against the raw source data; that validation once caught a number published as 23% when the source said 21.4%. See how we approach tracking for the checks we run before trusting any platform. If you want to know what’s really firing on your site before you commit, Sonar scans your tracking in one click.

Comparing tools usually means you’re about to invest real time in one. If your current numbers already look off, or you’re not sure whether it’s the tool or the tracking underneath it, that’s exactly what talking to us is built to catch, before you build reporting on a setup that won’t hold.