Open-source product analytics, built for engineers.

PostHog is one of the most-used analytics tools in 2026. Engineers and product teams who want product analytics, session replay, feature flags, and A/B testing in one tool, with the option to self-host. Especially strong for technical teams that hate sending all their user data to a third-party SaaS.

Who it's for: Engineers and product teams who want product analytics, session replay, feature flags, and A/B testing in one tool, with the option to self-host. Especially strong for technical teams that hate sending all their user data to a third-party SaaS.

Key features

Events Product analytics

Track every user action with autocapture or explicit events. SQL-powered insights so you can write queries instead of clicking through dashboards.

Replay Session replay

Watch real user sessions with console logs and network requests. The dev-tools-style inspector catches bugs the QA team would miss.

Flags Feature flags & A/B tests

Built-in feature flags tied directly to your analytics. Run an experiment and read the results in the same UI — no Segment plumbing required.

Self-host Open source

MIT-licensed. You can run the whole stack on your own infra if you don't want your analytics data leaving your VPC. This is rare and huge for regulated industries.

The honest take

✓ What works

Open source and self-hostable — your user data never has to leave your infra
Five products in one (analytics, replay, flags, experiments, surveys) for the price of one
SQL-native queries — engineers love this, marketers hate it
Free tier is genuinely usable (1M events/mo), not a bait-and-switch
Active development, ships new features weekly

✗ What doesn't

UI can feel dev-oriented — non-technical PMs may struggle vs. Amplitude/Mixpanel
Self-hosting requires real DevOps maturity — not for teams without a platform engineer
Documentation is decent but not as polished as Amplitude's
Mobile SDKs are younger than the web SDKs — iOS/Android have rough edges

Verdict

If you're an engineering-led product team that wants analytics, replays, feature flags, and A/B tests in one tool and you value data sovereignty, PostHog is the obvious choice. The free tier alone beats what most teams pay for. Marketing-led orgs will probably prefer Amplitude's UI.

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