GA4
Google Analytics 4, free web analytics
PostHog
Open-source product analytics + flags
GA4 is free web-and-app analytics tied to the Google ecosystem (Ads, BigQuery export, Search Console). PostHog is product analytics — event-first, user-identified, with flags + replay + experiments. GA4 wins for marketing / SEO / Ads attribution. PostHog wins for product-led and engineering-first teams.
Pick GA4 when you're marketing-focused and need Google Ads/SEO/BigQuery attribution.
Pick PostHog when you're product/engineering-focused and want user-level events + flags + replay.
| Feature | 📊GA4 | 🦔PostHog | Winner |
|---|---|---|---|
| Primary focus | Marketing / acquisition | Product / retention | Tie |
| Cost | Free (360 is $$) | Free tier, then usage | A |
| User identification | Limited (GDPR-cautious) | User + anonymous + merge | B |
| Session replay | No | Yes | B |
| Feature flags | No | Yes | B |
| Google Ads integration | Native | No | A |
| BigQuery export | Free / daily | Via CDP / paid | A |
| Funnels / retention | Basic | Product-grade | B |
Primary focus
TieGA4
Marketing / acquisition
PostHog
Product / retention
Cost
AGA4
Free (360 is $$)
PostHog
Free tier, then usage
User identification
BGA4
Limited (GDPR-cautious)
PostHog
User + anonymous + merge
Session replay
BGA4
No
PostHog
Yes
Feature flags
BGA4
No
PostHog
Yes
Google Ads integration
AGA4
Native
PostHog
No
BigQuery export
AGA4
Free / daily
PostHog
Via CDP / paid
Funnels / retention
BGA4
Basic
PostHog
Product-grade
Best for
Best for
Usually additive — install both. GA4 keeps handling marketing + SEO; PostHog handles in-product events. If consolidating: you can replace GA4 for most site uses with PostHog (add a UTM-parser plugin, pipe to BigQuery via Export), but you lose Google Ads auto-bidding optimization signals unless you send Enhanced Conversions another way.
GA4 is free web-and-app analytics tied to the Google ecosystem (Ads, BigQuery export, Search Console). PostHog is product analytics — event-first, user-identified, with flags + replay + experiments. GA4 wins for marketing / SEO / Ads attribution. PostHog wins for product-led and engineering-first teams. In short: GA4 — Google Analytics 4, free web analytics. PostHog — Open-source product analytics + flags.
Pick GA4 when you're marketing-focused and need Google Ads/SEO/BigQuery attribution.
Pick PostHog when you're product/engineering-focused and want user-level events + flags + replay.
Usually additive — install both. GA4 keeps handling marketing + SEO; PostHog handles in-product events. If consolidating: you can replace GA4 for most site uses with PostHog (add a UTM-parser plugin, pipe to BigQuery via Export), but you lose Google Ads auto-bidding optimization signals unless you send Enhanced Conversions another way.
Yes. Both have MCP servers installable via MCPizy (mcpizy install ga4 and mcpizy install posthog). They work identically across Claude Code, Claude Desktop, Cursor, Windsurf, and any other MCP-compatible client. You can install both side by side and route queries in your agent's prompt.
PostHog is the open-source all-in-one product analytics — events, funnels, feature flags, session replay, A/B tests, even a heatmap. Mixpanel is the polished dedicated product-analytics suite with the best query UX. PostHog wins on self-host + bundled features; Mixpanel wins on polish.
Amplitude is the enterprise product-analytics and CDP standard — deep segmentation, behavioral cohorts, and a mature governance story. PostHog is the open-source all-in-one — analytics + flags + replay + experiments. Amplitude wins on depth of analysis + enterprise; PostHog wins on cost + bundled features.
Not sure? Run both side by side — swap between them in your AI agent with a single config line.