PostHog

What Is PostHog?

Product analytics has fractured into a landscape of specialist tools. Amplitude for funnels and retention. Hotjar for session replay. LaunchDarkly for feature flags. Optimizely for A/B testing. Each solves a narrow problem, each requires its own integration, and each sends user data to a different third-party server. For European organisations navigating GDPR, every additional vendor multiplies compliance overhead.

PostHog takes the opposite approach: consolidate everything into a single open-source platform that teams can self-host or run on EU-hosted cloud. Founded in 2020 by James Hawkins and Tim Glaser — who met at a London regulatory tech startup — PostHog went through Y Combinator and has since raised $194 million through a Series E at a $1.4 billion valuation. The platform now combines product analytics, session replay, feature flags, A/B testing, surveys, error tracking, a data warehouse, and a customer data platform under one roof.

With approximately 160 employees working remotely across 20+ countries, PostHog operates as an all-remote company with roots in the UK. The EU Cloud instance runs in Frankfurt (AWS eu-central-1), ensuring data never leaves EU jurisdiction. Self-hosting on your own infrastructure eliminates third-party data transfers entirely. Over 90% of PostHog's users stay within the free tier — 1 million events, 5,000 recordings, and 1 million feature flag requests per month.

Key Features

Product Analytics

PostHog's analytics engine handles event tracking, funnels, retention analysis, path analysis, and lifecycle reporting. Trends visualise custom metrics over time. Funnels measure conversion between steps with breakdown by user properties. Retention cohorts track whether users return after initial activation. The query engine runs on ClickHouse, which provides fast aggregation across large event volumes. An AI assistant (Max) helps non-technical users build queries in natural language.

Session Replay

High-fidelity session recordings capture exactly what users see and do — clicks, scrolls, form interactions, and page transitions. Recordings link directly to analytics events, so teams can move from a funnel drop-off to the actual user session that dropped. Network performance monitoring captures request timing and errors. Console logs and exceptions are visible alongside the replay. Privacy controls allow masking sensitive fields and disabling recording on specific pages.

Feature Flags and A/B Testing

Feature flags control rollout of new functionality — percentage-based rollouts, targeting by user properties, and multivariate flags with multiple variants. A/B testing layers on statistical analysis: define a hypothesis, set a target metric, assign traffic splits, and PostHog calculates statistical significance automatically. Feature flags and experiments integrate directly with the analytics engine, so impact measurement happens without additional instrumentation.

Surveys and Feedback

No-code survey builder with multiple question types, targeting rules, and scheduling. Surveys appear in-app based on user behaviour — trigger a feedback prompt after a user completes onboarding, or ask about satisfaction after a support interaction. Responses pipe directly into PostHog's analytics, joining qualitative feedback with quantitative usage data. The free tier includes 250 survey responses per month.

Data Warehouse and Pipelines

PostHog syncs external data from Stripe, HubSpot, Salesforce, GitHub, and other sources into a built-in data warehouse. Data pipelines transform incoming events in real time and export to 25+ destinations including BigQuery, Snowflake, Redshift, and S3. This architecture means PostHog acts as both the analytics tool and the data integration layer — reducing the need for separate ETL infrastructure like Fivetran or Airbyte.

Pricing

PostHog's pricing model is radically transparent compared to the analytics industry norm. Every product has a generous free tier, and paid usage is strictly usage-based with no per-seat fees. A startup with three engineers and a company with three hundred both pay the same rate per event.

Product analytics costs approximately $0.00005 per event after the first free million — roughly $50 per additional million events. Session replay, feature flags, surveys, and error tracking each have separate free allowances and usage-based pricing. Critically, PostHog lets teams set hard billing caps per product. Hit the cap, and PostHog stops processing for that product until next month. No surprise invoices.

For context, Amplitude's Growth plan starts at $61/month for a limited event volume. Mixpanel charges based on tracked users. LaunchDarkly's feature flags start at $8.33/seat/month. PostHog bundles all of these capabilities with unified pricing and a single data layer.

Enterprise pricing adds SSO/SAML, advanced permissions, audit logs, and dedicated support with custom SLAs.

EU Compliance & Privacy

PostHog's EU compliance story has two paths. PostHog Cloud EU runs on AWS eu-central-1 in Frankfurt, Germany. All event data, session recordings, and user properties stay within EU borders. IP anonymisation is enabled by default on EU Cloud projects. A Data Processing Agreement covers the relationship between PostHog and its customers.

Self-hosting provides the strongest guarantee: deploy PostHog on your own infrastructure and no data reaches PostHog's servers. The open-source licence allows full audit of the codebase. This eliminates third-party data processor relationships entirely — the organisation is both data controller and processor.

The company holds SOC 2 Type II certification. PostHog supports cookieless tracking mode, which avoids the need for cookie consent banners in jurisdictions where analytics cookies require opt-in. One complication: PostHog Inc is incorporated in the US (Delaware) with UK operational roots. While the EU Cloud instance keeps data in Frankfurt, the corporate entity sits outside EU jurisdiction. Organisations with strict requirements around data processor domicile should evaluate whether EU Cloud hosting or self-hosting satisfies their compliance posture.

Who It's Best For

Product engineering teams who want analytics, session replay, and feature flags in a single platform without managing integrations between Amplitude, Hotjar, and LaunchDarkly. PostHog's unified data model means every tool queries the same event stream.

Startups and scale-ups where the generous free tier covers early-stage usage and usage-based pricing scales predictably. No per-seat fees mean the entire team has access from day one.

Self-hosting organisations in regulated industries — finance, healthcare, government — that need product analytics without sending user data to third-party servers. PostHog's open-source deployment gives full infrastructure control.

European companies prioritising EU data residency who want analytics hosted in Frankfurt with IP anonymisation and cookieless tracking, without the compliance overhead of US-only providers.

The Verdict

PostHog is the most comprehensive open-source product analytics platform available, and the EU Cloud option addresses the data residency concerns that make Google Analytics and Amplitude problematic for European organisations. The breadth is genuinely impressive — analytics, replay, flags, testing, surveys, warehouse, and CDP in one product. The trade-off is depth: each individual module is good but not best-in-class compared to dedicated tools. Amplitude's analytics are richer. LaunchDarkly's flag management is more sophisticated. Hotjar's replay has better heatmaps. PostHog bets that the value of integration outweighs the value of specialisation — and for most product teams, that bet pays off.

Frequently Asked Questions

Is PostHog GDPR compliant?

Yes. PostHog EU Cloud stores all data in Frankfurt (AWS eu-central-1) with IP anonymisation enabled by default. Self-hosting eliminates third-party data transfers. PostHog offers cookieless tracking and Data Processing Agreements for paid plans.

Can I self-host PostHog?

Yes. PostHog is open source (MIT licence for the core) and can be deployed on your own infrastructure using Docker or Kubernetes. Self-hosted deployments run on ClickHouse and require meaningful server resources — plan for at least 8 GB RAM and dedicated storage for production use.

How does PostHog compare to Google Analytics?

PostHog offers product analytics, session replay, feature flags, A/B testing, and surveys — far beyond GA4's scope. PostHog provides EU hosting, self-hosting, and no per-seat fees. GA4 is stronger for marketing attribution, advertising integration, and cost (free). PostHog replaces GA4 for product teams; marketing teams may need both.

Is PostHog really free?

Yes. The free tier includes 1 million analytics events, 5,000 session recordings, 1 million feature flag requests, and 250 survey responses per month with unlimited team members. Over 90% of PostHog users stay within these limits.

Where is PostHog data stored?

PostHog Cloud US uses AWS us-east-1 (Virginia). PostHog Cloud EU uses AWS eu-central-1 (Frankfurt). Self-hosted deployments store data on your own infrastructure. EU Cloud disables IP capture by default for new projects.