Courier vs Knock
An independent, review-free comparison compiled by the SaaSTracker editorial team. Both products are profiled in full, and neither can pay for placement here.
The short answer
Both sides assessedCourier compared with Knock
The two are direct competitors and the choice usually comes down to volume and shape. Courier is cheaper in the 10,000 to 100,000 message band ($500 at 100,000 sends versus Knock's $250 floor plus overage) and has the better visual design surface for non-developers. Knock has the more generous free tier at equal volume, deeper multi-tenancy, workflows as code with CI validation, and Guides for in-product messaging. Pick Courier for simplicity and design; pick Knock for B2B tenant complexity and notification logic in version control.
Knock compared with Courier
The closest comparison in the batch: both are bring-your-own-provider notification infrastructure with in-app inboxes, preference centers, and multi-channel workflows. Courier is metered purely per send at $0.005 with 10,000 free, and leans harder into the visual template designer for non-developers. Knock has the stronger free tier, deeper multi-tenancy, workflows as code, and Guides. Pick Courier for simpler linear pricing and a friendlier design surface; pick Knock for B2B products with tenant-level configuration and teams who want notification logic in version control.
Choose Courier if
Engineering teams at product companies who already pay for SendGrid, Twilio, or Firebase and want an orchestration layer over them, particularly mixed teams where a non-developer needs to own the message content without filing tickets.
Choose Knock if
Product and engineering teams at SaaS companies who need real product notifications (in-app feed, digests, preference centers, per-tenant configuration) and want the workflow logic owned by a platform a PM can edit rather than by application code an engineer has to redeploy.
Side by side
13 attributes| Attribute | Courier | Knock |
|---|---|---|
| Category | Automation | Automation |
| Starting price | $0 (Developer, 10,000 sends per month), then $0.005 per send (free plan available) | $0 (Developer), then $250 per month (Starter) (free plan available) |
| Pricing model | Pure usage-based pricing on notifications sent, with no per-seat fee and no channel add-on charges, plus a free monthly allowance and a quoted enterprise tier with volume discounts. | Usage-based on messages sent, with a separate meter for Guide active users and AI agent credits, plus a large free tier and a single published paid plan before enterprise contracts. |
| Free plan | Developer includes 10,000 notification sends per month across email, push, SMS, in-app, and chat. | Developer includes 10,000 messages a month, 500 Guide active users, 500 AI agent credits, unlimited workflows, unlimited channels, unlimited team members, batching, delays, broadcasts, multi-tenancy, and Google SSO. |
| Free trial | No time-limited trial; the Developer plan is permanently free within its send allowance | No time-limited trial; the Developer plan is permanently free |
| Best for | Engineering teams at product companies who already pay for SendGrid, Twilio, or Firebase and want an orchestration layer over them, particularly mixed teams where a non-developer needs to own the message content without filing tickets. | Product and engineering teams at SaaS companies who need real product notifications (in-app feed, digests, preference centers, per-tenant configuration) and want the workflow logic owned by a platform a PM can edit rather than by application code an engineer has to redeploy. |
| Setup time | An afternoon to a first notification in production: connect a provider, design a template, call the API. Migrating an existing notification service takes one to two sprints and is usually done one notification type at a time. | A day to a first workflow in production for a competent backend engineer, and one to three sprints to migrate an existing homegrown notification service. The in-app feed component is typically the fastest visible win. |
| Learning curve | Low. The core concepts (providers, templates, routing, preferences, automations) map closely to how teams already think about notifications, and the visual designer means content people onboard in minutes rather than days. | Low for engineers, moderate for product people. The concepts (workflows, recipients, tenants, channels, preferences) are clean, but the mental model of moving decision logic out of application code into a workflow platform takes a team a couple of weeks to internalize. |
| Platforms | Web dashboard, REST API, React and JavaScript components, iOS, Android, React Native, and Flutter SDKs | Web dashboard, REST API, CLI, React and JavaScript components, iOS, Android, React Native, and Flutter clients, MCP server |
| Compliance | SOC 2, GDPR | SOC 2, GDPR, CCPA, HIPAA with a BAA on Enterprise |
| Founded | 2019 | 2021 |
| Headquarters | San Francisco, California, United States | New York, New York, United States |
| Ownership | Venture-backed | Venture-backed |
Strengths and limitations
Courier
Strengths
- The simplest pricing in the category: no seats, no channel fees, no contact meter, just $0.005 a send with 10,000 free every month.
- Fifty-plus provider integrations with your own credentials, which means no vendor lock-in, no reputation rebuild, and no renegotiated contracts.
- The visual template designer with multi-channel preview on one canvas is the friendliest content surface among the developer-first notification tools.
- Batching, throttling, delays, and conditions cover the notification-fatigue problem that most in-house implementations get wrong.
Limitations
- Nothing works without engineering; the API call has to come from your application, so a marketer cannot get value alone.
- Delivery is not included, so the sticker price understates the real cost and you own deliverability, domain authentication, and list hygiene entirely.
- Multi-tenancy is less developed than Knock's, which matters for B2B products giving each customer organization its own notification configuration.
- Role-based access control and EU data residency are Enterprise-only, so a European mid-market buyer with residency requirements cannot self-serve.
Knock
Strengths
- Batching, digests, preference centers, and multi-tenancy are all first-class, and they are exactly the four things engineering teams build worst when they build them in-house.
- The free Developer tier is extraordinarily generous, including unlimited workflows, unlimited channels, unlimited team members, and multi-tenancy at $0.
- Bring-your-own-provider means you keep your sending reputation, your existing SendGrid or Twilio contracts, and your negotiated rates.
- Workflows as code with CLI, version control, CI validation, environments, and one-click rollback, which makes notification changes a normal part of the software lifecycle instead of a risk.
Limitations
- Completely unusable without engineering; there is no path where a marketer signs up and gets value, because nothing happens until code calls the API.
- The pricing cliff from $0 to $250 a month with no intermediate plan penalizes exactly the small companies the free tier attracted.
- Guides are metered separately on active users, so the in-product messaging feature has its own cost curve that is easy to miss when budgeting.
- You still pay for delivery separately, and you still own deliverability, list hygiene, and domain authentication yourself.
Pricing compared
Courier
Pure usage-based pricing on notifications sent, with no per-seat fee and no channel add-on charges, plus a free monthly allowance and a quoted enterprise tier with volume discounts.
- Developer$0
- Business$0.005
- EnterpriseCustom
Courier's pricing is the easiest to reason about in this whole category and, at low to moderate volume, extremely fair. Ten thousand free sends a month covers a real early-stage product, and $0.005 a send with no seat fees and no channel charges means the bill scales exactly with usage and nothing else. Against Knock, Courier is dramatically cheaper in the 10,000 to 50,000 message band, where Knock's $250 floor bites hard. The break-even flips at high volume: 400,000 sends costs $2,000 on Courier and would be an Enterprise negotiation on either platform. What you are not getting for the money is delivery, deliverability, or any marketing capability, and the honest total cost of ownership always includes the provider invoices sitting underneath.
Knock
Usage-based on messages sent, with a separate meter for Guide active users and AI agent credits, plus a large free tier and a single published paid plan before enterprise contracts.
- Developer$0
- Starter$250
- EnterpriseCustom
Knock is priced as infrastructure, and the honest comparison is not against Mailchimp but against the salary cost of the engineer who would otherwise own your notification service. On that basis the free tier is remarkable value and Starter at $250 is fair, since 50,000 messages with batching, preference centers, in-app feed, and multi-tenancy is a quarter of engineering work you no longer do. The weakness is the plan gap: a team sending 15,000 messages a month is paying $250 for capability it barely uses, and the separate Guides meter means the sticker price understates the cost of using the whole product. Add your own provider bills on top and Knock is never the cheapest line on the invoice, but it is usually the one that saves the most.
Editorial verdict on each
Courier
Courier is the notification orchestration layer to pick when you want the least complicated bill and the friendliest content surface. Ten thousand free sends a month is enough for a real early-stage product, $0.005 a send with no seats and no channel fees is the most predictable pricing in this category, and the visual designer with multi-channel preview means the person writing the notification does not need an engineer to publish it. Set against Knock, its nearest rival, Courier wins on price in the low and middle volume bands and on design ergonomics, and loses on multi-tenancy depth and workflows-as-code discipline. The hard limits are structural rather than fixable: delivery is not included, deliverability is entirely your problem, there is no marketing capability, and the per-send rate makes broadcast sending economically silly. For a five-person startup whose product needs to notify people without annoying them, Courier is the cheapest sensible starting point in this batch. For a five-person startup whose problem is lifecycle marketing, it is the wrong shelf entirely.
Read the full Courier profileKnock
Knock is the right purchase when your notification problem is a product problem rather than a marketing problem. If people are complaining about email volume, if a preference center keeps slipping down the roadmap, if enterprise customers want Slack delivery, or if an engineer already owns a homegrown notification service they resent, this is the layer to buy and the free Developer tier is generous enough to prove it in a weekend. The reasons to walk away are equally clear: there is no marketing surface, nothing works without engineering, you still pay your own providers, and the leap from $0 to $250 a month with nothing in between is genuinely painful for a small team. For a five-person startup, Knock is the first thing to reach for only if you are shipping a product with an in-app notification feed. If your immediate need is onboarding emails and lifecycle campaigns, start with Customer.io, Bento, or Dittofeed and add Knock later when the product notifications become their own problem.
Read the full Knock profileCourier profile last reviewed 2026-08-22; Knock last reviewed 2026-08-22. Pricing is compiled from public sources and can change without notice. See our methodology.