Knock vs Courier
Code-first workflow engine versus visual-journey notification platform.
What matters for developers picking email infrastructure
The question here is which one a backend engineer would rather operate. That means SDK depth in the language already in use, whether a retry can safely be replayed, how much the event log tells you when a customer says the email never arrived, and whether the pricing curve stays sane as volume grows.
| Priority | Knock | Courier |
|---|---|---|
| DX score | 9/10 | 8/10 |
| SDKs | node, python, go, ruby, php, elixir, java, dotnet | node, python, go, ruby, php, java |
| Idempotency keys | Yes | No |
| Operating since | 2021 | 2019 |
| Event stream | Yes | Yes |
| Best published rate per 1,000 | Tiers not published in comparable form | Tiers not published in comparable form |
| Webhooks | Yes | Yes |
| Deliverability | Inherits the deliverability of the provider you BYO (Postmark, SendGrid, Resend). | Inherits providers you connect. |
| Free tier | 10,000 notifications/mo | 10,000 sends/mo |
For a developer-owned stack running password resets, receipts, and magic links shipped from application code, Knock takes developer experience, SDK breadth, and idempotency keys, while Courier takes operating track record. On free tier, Knock offers 10,000 notifications/mo against 10,000 sends/mo from Courier. That ordering reflects this audience. Weigh the same table differently and the answer changes.
Side by side
| Feature | Knock | Courier |
|---|---|---|
| DX score | 9/10 | 8/10 |
| SDKs | node, python, go, ruby, php, elixir, java, dotnet | node, python, go, ruby, php, java |
| Webhooks | Yes | Yes |
| Deliverability | Inherits the deliverability of the provider you BYO (Postmark, SendGrid, Resend). | Inherits providers you connect. |
| Free tier | 10,000 notifications/mo | 10,000 sends/mo |
| Tagline | Notification infrastructure with workflow engine. | Notification infrastructure with visual journeys. |
| Starts at | $249/mo (Starter) | $95/mo (Business) |
| Pricing model | volume | volume |
| API | Yes | Yes |
| SMTP | No | No |
| Templates | rich | rich |
| React Email | Yes | No |
| Inbound | No | No |
| Multi-tenant | Yes | Yes |
| Idempotency | Yes | No |
| Dedicated IP | No | No |
| Best for | Teams that need multi-channel product notifications with preferences. | Teams that need both product notifications and marketing-style journeys. |
Knock
- ›Strong workflow engine
- ›In-app feed component
- ›Deep SDK coverage
- ›Idempotency keys
- ›Pricier than running your own; entry plan is steep
- ›Bring your own delivery provider
Courier
- ›Visual journey editor
- ›Native Slack/Teams routing
- ›Drop-in inbox component
- ›Less code-first than Knock
- ›Pricing climbs with volume