Amplitude vs PostHog
Both are analytics tools. Here is what separates them.
What Amplitude is
Amplitude is a product analytics platform for tracking what people do inside a web or mobile app and turning that behaviour into cohorts, funnels and retention curves. It is sold as a set of named modules: Product Analytics, Marketing Analytics, Session Replay, Heatmaps, Guides and Surveys, Feature Experimentation, Web Experimentation and Data Governance. Pricing follows event volume rather than headcount. Every plan, the free one included, comes with unlimited seats, so adding a colleague who only reads dashboards costs nothing. Free covers 2 million events a month with no credit card, and includes 10,000 session replays and 2,000 AI feedback records. Plus also starts at $0, because the first 2 million events are free, and scales to 70 million events a month with two years of data retention and 20 behavioural cohorts. Growth and Enterprise move to custom event-based pricing quoted by sales, with 20,000 and 50,000 monthly session replays respectively. Product Analytics is the core: cohort, churn, retention, funnel, conversion and milestone analysis, plus a Conversion Drivers view that looks specifically at the users who completed every stage of a funnel. Alerts and heatmaps unlock from the Plus plan upward. Session Replay records individual sessions on the web through either the Browser SDK or a standalone SDK, and on iOS, Android and React Native. Text is masked by default and retention limits can be set to suit. It also works with the User Privacy API and the DSAR API, so deletion and subject access requests can be answered without unpicking recordings by hand. Experiment puts feature flags and testing in the same account as the analytics. Flags can be deployed client-side or server-side, with local evaluation for low latency and remote evaluation when targeting depends on user context, and the whole thing is exposed through APIs so rollouts can be driven from a CI/CD pipeline. The statistical options go past a plain T-test to sequential testing, CUPED, multi-armed bandits, mutual exclusion groups and holdouts. Access control tightens with the plan. SSO and project permissions need Growth or higher, and role-based access control is Enterprise only. Amplitude MCP pulls insights out into an external AI tool, and Active AI Visibility prompts are capped at 500 on Free, 1,000 on Plus, 2,500 on Growth and 5,000 on Enterprise.
What PostHog is
PostHog is a bundle of product tools that sit under one account, covering product analytics, web analytics, session replay, feature flags, experiments, surveys, error tracking, logs, LLM observability, a managed data warehouse and a customer data platform. Analytics starts with autocapture, which records pageviews, clicks and form submissions without per event tracking code being written first. On top of that sit funnels, retention curves, path analysis, trends, dashboards and direct SQL querying for the questions the built-in views do not answer. Incoming events can be transformed before they are stored, including IP anonymisation and hashing of personal data. Session replay has SDKs for web, React Native, iOS, Android and Flutter. Recordings can be sampled, or gated by URL or by feature flag, so that only chosen sessions are captured, and text, inputs or whole elements can be masked on the device before a recording is sent. Retention runs to 30 days on the free plan, 90 days on pay as you go, one year on Boost and Scale, and five years on Enterprise. One detail catches people out: changing the retention setting applies only to recordings captured after the change, because existing recordings keep the period they were captured under. Feature flags support percentage rollouts, targeting by individual user or by group, multivariate variants and JSON payloads. The free tier is metered monthly. It covers one million analytics events, one million feature flag requests, 5,000 session recordings, one million data warehouse rows, 10 GB of ingested logs, 100,000 tracked exceptions and 1,500 survey responses. Usage past those allowances is charged per unit, starting at 0.00005 USD per analytics event, 0.0001 USD per feature flag request, 0.0050 USD per session recording, 0.000015 USD per data warehouse row and 0.10 USD per survey response. An account with no card on file is limited to one project and one year of data retention. Adding a card raises that to six projects, seven years of data retention and email support. PostHog Cloud is offered in a United States region and a European region hosted in Frankfurt. Public event capture endpoints live at us.i.posthog.com and eu.i.posthog.com, with private management endpoints at us.posthog.com and eu.posthog.com. The API accepts personal API keys, project secret API keys and OAuth, and the public POST-only endpoints are not rate limited. Self-hosting is possible but limited. The Docker Compose deployment is released under the MIT licence and wants roughly 4 vCPU, 16 GB of RAM and more than 30 GB of storage running Ubuntu Linux, but it is officially unsupported and carries no guarantees. Paid plan features are available only on PostHog Cloud, so a self-hosted instance runs the free feature set.
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