Paddle vs Knock
Merchant of Record for SaaS — global tax, billing, checkout in one
vs. Notifications-as-a-service: in-app feeds, email, push, SMS, chat via one API
Pricing tiers
Paddle
Pay-as-you-go
5% + 50¢ per Checkout transaction. No monthly fee. All-inclusive (tax, fraud, support).
$0 base (usage-based)
Enterprise
Custom rates for high-volume. Dedicated success. Custom migration + implementation.
Custom
Invoicing (<$10 products)
Custom pricing for invoicing / products under $10.
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 payg on Paddle vs starter on Knock.
| Metric | Paddle | Knock |
|---|---|---|
| guide users | — | 2500 users |
| guide users overage | — | $0.05/user USD/user |
| messages monthly | — | 50000 messages/mo |
| messages overage | — | $0.005/message USD/message |
Features
Paddle · 12 features
- Affiliates (Rewardful partnership) — Affiliate tracking (via partner).
- Customer Portal — Self-service subscription management.
- Fraud Protection — ML + human review. Paddle absorbs chargebacks.
- Global Tax Compliance — Automatic VAT/GST/sales tax calc + remittance + filing.
- One-time Sales — Perpetual license sales, single purchases.
- Paddle Checkout — Hosted or overlay checkout. Localized + fraud-protected.
- Paddle Retain — Revenue recovery + cancel flows (acquired Retain).
- ProfitWell Analytics — Included subscription analytics (acquired ProfitWell).
- Self-Serve Invoices — B2B invoicing with custom POs.
- Smart Dunning — Retry logic + email sequences for failed payments.
- Subscriptions — Full lifecycle: trials, changes, cancellations, recovery.
- Webhooks — Standard resource events with HMAC signing.
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 | Paddle | Knock |
|---|---|---|
| CLI | — | Knock CLI |
| SDK | Paddle.js, @paddle/paddle-node-sdk, paddle-python | knockapi (Python), knockapi (Ruby), knock-elixir, knock-go, knock-java, @knocklabs/node, @knocklabs/react |
| REST | Paddle Billing API | Knock REST API |
| MCP | — | Knock MCP Server |
| OTHER | Paddle Checkout, Paddle Webhooks | Outbound Webhooks |
Staxly is an independent catalog of developer platforms. Some links to Paddle and Knock may be affiliate links — Staxly may earn a commission if you sign up through them, at no extra cost to you. Pricing is verified against vendor pages at publication time — reconfirm before buying.
Want this comparison in your AI agent's context? Install the free Staxly MCP server.