PostHog vs Knock
Open source product analytics — all-in-one dev tool
vs. Notifications-as-a-service: in-app feeds, email, push, SMS, chat via one API
Pricing tiers
PostHog
Free (generous)
No credit card. Each product has its own free monthly quota. Great for startups + OSS.
Free
Paid (usage-based)
Pay only what you use, after free quotas. Volume discounts at higher tiers. 6 projects, 7-year retention.
$0 base (usage-based)
Self-Hosted (OSS)
MIT-licensed. Run on your own infra via Docker/k8s. Zero vendor lock-in.
$0 base (usage-based)
Enterprise
Custom. SAML SSO, dedicated CSM, custom SLA.
Custom
Knock
Developer
Free forever. 10K messages, 500 guide users, 500 AI credits/month.
$0 base (usage-based)
Starter
$250/mo. 50K messages, 2.5K guide users, 2K AI credits. Remove branding.
$250/mo
Enterprise
Custom pricing. White-label, i18n, data warehouse, Datadog, SCIM, SAML, HIPAA/BAA.
Custom
Free-tier quotas head-to-head
Comparing free on PostHog vs starter on Knock.
| Metric | PostHog | Knock |
|---|---|---|
| data warehouse rows | 1000000 rows/month | — |
| error tracking exceptions | 100000 exceptions/month | — |
| feature flags requests | 1000000 requests/month | — |
| guide users | — | 2500 users |
| guide users overage | — | $0.05/user USD/user |
| llm analytics events | 100000 events/month | — |
| logs gb | 50 GB/month | — |
| messages monthly | — | 50000 messages/mo |
| messages overage | — | $0.005/message USD/message |
| product analytics events | 1000000 events/month | — |
| projects | 1 projects | — |
| retention years | 1 year | — |
| session replay recordings | 5000 recordings/month | — |
| surveys responses | 1500 responses/month | — |
| team members | unlimited members | — |
Features
PostHog · 14 features
- A/B Testing — Experiments with significance analysis.
- Data Pipelines — Export events to BigQuery, Snowflake, S3.
- Data Warehouse — Query external sources (Stripe, Hubspot, S3) alongside events with SQL.
- Error Tracking — Sentry-style error tracking in same platform.
- Feature Flags — Rollout flags with targeting, A/B testing, JSON payloads.
- LLM Analytics — Tracing + cost tracking for OpenAI, Anthropic, Gemini, etc.
- Logs — Centralized log ingest with free 50 GB/month.
- Product Analytics — Events, funnels, trends, retention, paths. SQL insights available.
- Revenue Tracking — Integration with Stripe for revenue + churn metrics.
- Self-Hosting — Docker/Helm. Full feature parity with cloud.
- Session Replay — Watch user sessions. Privacy controls, masked inputs, JS errors.
- SQL Query API — Run ClickHouse SQL over your events via API.
- Surveys — In-app surveys + feedback widgets.
- Workflows — Trigger emails/webhooks on events.
Knock · 13 features
- AI Agents — Autonomous notification drafting & workflow generation.
- Batch + Digest — Group notifications into digests on schedule or window.
- Chat — Slack, Microsoft Teams, Discord.
- Email — Send via SendGrid/Postmark/Resend/Mailgun/AWS SES as relays.
- Guides — In-product messaging, announcements, modals, banners.
- i18n / Localization — Translate templates by user locale.
- In-App Feed — Notification inbox with React/Vue/iOS/Android drop-in components.
- Multi-tenancy — Per-tenant branding, preferences, quiet hours.
- Outbound Webhooks — Subscribe to delivery events.
- Preferences — User + tenant preference center with granular controls.
- Push — iOS (APNs), Android (FCM), Expo, Web Push.
- SMS — Twilio, MessageBird, Telnyx, Vonage as providers.
- Workflows — Visual notification orchestration (branch, batch, delay, throttle).
Developer interfaces
| Kind | PostHog | Knock |
|---|---|---|
| CLI | — | Knock CLI |
| SDK | posthog-android, posthog-flutter, posthog-go, posthog-ios (Swift), posthog-js, posthog-node, posthog-php, posthog-python, posthog-react-native, posthog-ruby | knockapi (Python), knockapi (Ruby), knock-elixir, knock-go, knock-java, @knocklabs/node, @knocklabs/react |
| REST | PostHog REST API | Knock REST API |
| MCP | PostHog MCP | Knock MCP Server |
| OTHER | Webhooks + Actions | Outbound Webhooks |
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