Courier vs GrowthBook
Notification API with multi-channel orchestration, templates, and preferences
vs. Open-source feature flags + experimentation — Warehouse Native
Pricing tiers
Courier
Free
Up to 10,000 notifications/month. All channels. Community support.
Free
Business
From $99/mo. Higher volumes, advanced routing, preference center, branding removal.
$99/mo
Enterprise
Custom. SOC 2, SSO, dedicated support, volume discounts, SLA.
Custom
GrowthBook
Open Source (Self-Host)
MIT-licensed. Unlimited everything. Community support.
$0 base (usage-based)
Cloud — Starter (Free)
Up to 3 users. Unlimited flags + experiments. Warehouse Native included.
Free
Cloud — Pro
$40/user/month. Up to 50 users. Advanced stats, visual A/B editor, CUPED, sequential testing, bandits.
$40/mo
Cloud — Enterprise
Custom. Unlimited users, SSO/SAML, approval flows, data pipelines, exportable audit logs.
Custom
Self-Host Enterprise
Open Source + Enterprise license. Visual A/B editor, advanced metrics, SSO/SAML, approvals, training.
Custom
Free-tier quotas head-to-head
Comparing free on Courier vs oss on GrowthBook.
| Metric | Courier | GrowthBook |
|---|---|---|
| notifications monthly | 10000 notifications/mo | — |
Features
Courier · 13 features
- Chat — Slack, Microsoft Teams, Discord, Mattermost.
- Email — SendGrid, Postmark, Mailgun, AWS SES, Resend, SMTP.
- Inbox (In-App) — React/JS drop-in in-app inbox component.
- Lists — Segment recipients for bulk notification sends.
- Logs + Analytics — Per-message delivery timeline + engagement.
- Multi-channel Routing — Provider failover + preferred channel per user.
- Notification Designer — Visual editor for templates across channels.
- Preferences — Per-user notification preferences hub.
- Push — APNs, FCM, Expo, OneSignal.
- Send API — POST /send with template + recipients + data.
- SMS — Twilio, MessageBird, Vonage, Plivo, Telnyx.
- Templates + Versioning — Template brands, variants, localization, version history.
- Webhooks — Delivery + engagement event webhooks.
GrowthBook · 15 features
- Approval Flows — Require reviewer approval on flag changes. Enterprise.
- Audit Logs — Full change history. Exportable on Enterprise.
- Dimensions & Slicing — Break down experiment results by user dimensions.
- Edge SDK Support — Cloudflare Workers, Lambda@Edge, Fastly, Akamai EdgeWorkers, Netlify Edge.
- Experiments — A/B/n with CUPED variance reduction + sequential testing.
- Feature Flags — Boolean + string + number + JSON flags with targeting.
- Feature Reviews (PR-style) — Draft → review → approve flag changes.
- Guardrail Metrics — Auto-monitor key metrics during experiments.
- Metric Catalog — Define + reuse metrics across experiments.
- Multi-Armed Bandits — Adaptive traffic allocation. Pro+.
- Safe Rollouts — Guarded gradual rollouts with automatic rollback.
- SSO / SAML — Enterprise SSO for cloud + self-host EE.
- Sticky Bucketing — User stays in variant even after eligibility changes.
- Visual A/B Test Editor — No-code DOM editor for web experiments. Pro+.
- Warehouse Native — Connect your warehouse + run experiments against your events data.
Developer interfaces
| Kind | Courier | GrowthBook |
|---|---|---|
| CLI | Courier CLI | — |
| SDK | courier-go, courier-java, @trycourier/courier, trycourier (Python), @trycourier/react-inbox, trycourier (Ruby) | Edge SDKs (CF Workers / Lambda@Edge / Fastly / Akamai), growthbook-android, growthbook-flutter, growthbook-go, growthbook-java, growthbook-node, growthbook-php, growthbook-python, growthbook-ruby, growthbook-swift, sdk-javascript, sdk-react |
| REST | Courier REST API | GrowthBook REST API |
| OTHER | Courier Studio, Outbound Webhooks | Webhooks |
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