head to head
Knock vs Courier
Code-first workflow engine versus visual-journey notification platform.
What matters for teams choosing a transactional API
Judged purely as an API. What the request contract guarantees on retry, how complete the webhook event coverage is, whether suppressions are readable and writable programmatically, and how much the message log retains when something needs debugging in production.
| Priority | Knock | Courier |
|---|---|---|
| Idempotency keys | Yes | No |
| Webhooks | Yes | Yes |
| Event stream | Yes | Yes |
| Operating since | 2021 | 2019 |
| Suppressions API | Yes | Yes |
| Best published rate per 1,000 | Tiers not published in comparable form | Tiers not published in comparable form |
| Batch sending | Yes | Yes |
| SDKs | node, python, go, ruby, php, elixir, java, dotnet | node, python, go, ruby, php, java |
| Deliverability | Inherits the deliverability of the provider you BYO (Postmark, SendGrid, Resend). | Inherits providers you connect. |
For a transactional workload running high-frequency programmatic sends where a missed delivery is a product failure, Knock takes idempotency keys and SDK breadth, while Courier takes operating track record. That ordering reflects this audience. Weigh the same table differently and the answer changes.
Side by side
| Feature | Knock | Courier |
|---|---|---|
| Webhooks | Yes | Yes |
| SDKs | node, python, go, ruby, php, elixir, java, dotnet | node, python, go, ruby, php, java |
| Deliverability | Inherits the deliverability of the provider you BYO (Postmark, SendGrid, Resend). | Inherits providers you connect. |
| Tagline | Notification infrastructure with workflow engine. | Notification infrastructure with visual journeys. |
| Free tier | 10,000 notifications/mo | 10,000 sends/mo |
| 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 |
| DX score | 9/10 | 8/10 |
| Best for | Teams that need multi-channel product notifications with preferences. | Teams that need both product notifications and marketing-style journeys. |
Knock
pros
- ›Strong workflow engine
- ›In-app feed component
- ›Deep SDK coverage
- ›Idempotency keys
cons
- ›Pricier than running your own; entry plan is steep
- ›Bring your own delivery provider
Courier
pros
- ›Visual journey editor
- ›Native Slack/Teams routing
- ›Drop-in inbox component
cons
- ›Less code-first than Knock
- ›Pricing climbs with volume