PostHog — Open Source Product Analytics & Session Replay

What it is

PostHog is an open-source product analytics platform that combines event tracking, session replay, feature flags, A/B testing, and a data warehouse in a single self-hosted application. It replaces the need for separate tools like Google Analytics, Hotjar, LaunchDarkly, and Optimizely.

PostHog is for product teams who want full control over their analytics data. It suits startups and enterprises that need product insights without sending user behavior data to third-party services.

How it saves time or tokens

This workflow provides a single Docker command that launches a working PostHog instance. Instead of configuring multiple analytics tools separately, you get everything in one deployment. The included JavaScript snippet auto-captures page views, clicks, and form submissions without manual event instrumentation.

How to use

1. Deploy PostHog with Docker:

docker run -d --name posthog \
  -p 8000:8000 \
  -v posthog_data:/var/lib/postgresql/data \
  posthog/posthog:release

1. Open http://localhost:8000 and complete the setup wizard. Create your organization and first project.

1. Add the PostHog snippet to your application:

<script>
  !function(t,e){var o,n,p,r;e.__SV||(window.posthog=e,e._i=[],e.init=function(i,s,a){function g(t,e){var o=e.split(".");2==o.length&&(t=t[o[0]],e=o[1]),t[e]=function(){t.push([e].concat(Array.prototype.slice.call(arguments,0)))}}(p=t.createElement("script")).type="text/javascript",p.async=!0,p.src=s.api_host+"/static/array.js",(r=t.getElementsByTagName("script")[0]).parentNode.insertBefore(p,r);var u=e;for(void 0!==a?u=e[a]=[]:a="posthog",u.people=u.people||[],u.toString=function(t){var e="posthog";return"posthog"!==a&&(e+="."+a),t||(e+=" (stub)"),e},u.people.toString=function(){return u.toString(1)+".people (stub)"},o="capture identify alias people.set people.set_once set_config register register_once unregister opt_out_capturing has_opted_out_capturing opt_in_capturing reset isFeatureEnabled onFeatureFlags getFeatureFlag getFeatureFlagPayload reloadFeatureFlags group updateEarlyAccessFeatureEnrollment getEarlyAccessFeatures getActiveMatchingSurveys getSurveys".split(" "),n=0;n<o.length;n++)g(u,o[n]);e._i.push([i,s,a])},e.__SV=1)}(document,window.posthog||[]);
  posthog.init('your-project-api-key', {api_host: 'http://localhost:8000'})
</script>

Example

// Custom event tracking
posthog.capture('purchase_completed', {
  product_id: 'prod_123',
  amount: 49.99,
  currency: 'USD'
});

// Feature flag check
if (posthog.isFeatureEnabled('new_checkout_flow')) {
  renderNewCheckout();
} else {
  renderClassicCheckout();
}

// Identify users
posthog.identify('user_123', {
  email: 'user@example.com',
  plan: 'pro'
});

Related on TokRepo

• Monitoring tools -- Observability and analytics platforms
• Self-hosted tools -- Run your own infrastructure

Common pitfalls

• The Docker single-container deployment is for evaluation only. Production deployments need separate PostgreSQL, Redis, ClickHouse, and Kafka instances. Use the PostHog Helm chart for Kubernetes.
• Auto-capture records every click and page view, which can generate high event volumes. Use the autocapture config option to filter unnecessary events.
• Session replay recordings consume significant storage. Set retention policies to avoid running out of disk space.