Overview
PostHog is an open-source product analytics suite whose modules include feature flags alongside analytics, session replay, experiments and surveys. Feature flags are billed by the number of API requests made to evaluate flags at the /flags endpoint, not by the $feature_flag_called events that record exposures[13][12]. The first million requests each month are free; beyond that, published rates fall from US$0.0001 per request between 1 and 2 million to US$0.00001 per request above 50 million[12]. PostHog states that more than 90% of companies use it for free, requires no card to start and lets customers set billing limits[12].
Server-side local evaluation reduces costs: each definitions poll costs ten requests when definitions changed and one when they did not, so one server instance polling every 30 seconds uses about 86,400 requests per month, while SDKs without ETag support use about 864,000[12]. The advantage of PostHog is that flags, experiments and the analytics used to judge them share one event pipeline. The limitations are that its flag governance (approvals, environments) is lighter than LaunchDarkly or Unleash Enterprise, and client-side heavy apps can generate many billable requests.
What PostHog does
- Product and web analytics
- Session replay
- Feature flags and A/B experiments
- Surveys
- Built-in data warehouse and sources
- Error tracking and logs
- Web and product analytics on one event stream
- Session replay, 5,000 free recordings a month
PostHog pricing
Free every month: 1M analytics events, 5K recordings, 1M flag requests, 100K exceptions, 1,500 survey responses, 10 GB logs; 1 project, 1-year retention. Pay-as-you-go: usage above free tier, 6 projects, 2-year retention, per-product billing limits. Platform packages (Boost, Scale, Enterprise) add SSO, audit logs and longer retention; onboarding call US$80.
PostHog strengths and limitations
Strengths
- Many tools under one bill
- Per-product free tiers reset monthly
- Billing limits prevent surprise charges
- Open-source and self-host option
- Fully published, volume-discounted pricing
- Web analytics bundled with product analytics
Limitations
- Developer-centric interface
- Per-unit rates require calculator
- Free plan limited to one project
- Individual modules less deep than specialists
- Broader and more complex than traffic-only tools
- Event costs grow with traffic
Appears in
- Best Product Analytics Tools in 2026 #3
- Best Feature Flag Tools in 2026 #6
- Best Heatmap Tools in 2026 #8
- Best Web Analytics Tools in 2026 #5
PostHog alternatives and competitors
Alternatives to PostHog: companies ranked in the same lists.
Mixpanel
Matomo
Amplitude
Google Password Manager
Microsoft Clarity
Statsig
Fullstory
Heap (Contentsquare)
Fathom Analytics
Simple Analytics
Plausible Analytics- Contentsquare (incl. Hotjar)
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