Knock
Customer engagement infrastructure for product-led growth
Postmark
Email for web applications
Updated February 2026
| Knock | Postmark | |
|---|---|---|
| Rating | 5.0★ | 5.0★ |
| Reviews | 3 | 17 |
| Pros | 13 | 9 |
| FactScore™ | 30.1 | 62.8 |
FactScore™ Comparison
FactScore™ weighs both quality (rating) and popularity (reviews) for a fairer ranking than stars alone.
Pros & Cons
Only in Knock — Pros
Cancelling notifications Complex notification workflows Developer first platform Easy-to-use API GUI for notification flows In-app notification feed Out-of-the-box integrations Reliable Responsive support Scheduling notifications Smooth workflow TemplatingBoth tools — Pros
Excellent documentationOnly in Postmark — Pros
Reliable email delivery Fast performance Human support Transactional email Affordable pricing Email templates Simple API Spam filterOnly in Knock — Cons
Lack of automated testing support Lack of declarative workflow definitionBoth tools — Cons
—Only in Postmark — Cons
—Details
| Knock | Postmark | |
|---|---|---|
| Categories | Email marketing, Marketing automation platforms, Unified API, AI Infrastructure Tools | Email clients, Email marketing |
| Platforms | Web | Web · iOS |
| Became Popular | March 17, 2022 | July 23, 2014 |
| Website | knock.link | postmarkapp.com |
Who Should Pick Which?
Choose Knock if...
- Cancelling notifications
- Complex notification workflows
- Developer first platform
Choose Postmark if...
- Reliable email delivery
- Fast performance
- Human support
With a FactScore™ of 30.1 vs 62.8, Postmark leads in community reception. Knock uniquely offers Cancelling notifications and Complex notification workflows, while Postmark stands out for Reliable email delivery and Fast performance.
What Users Say
Knock
Knock is a very easy-to-use API that makes adding all sorts of user notifications to your application a breeze. The GUI for adding notification flows is nicely designed and the documentation is wel...
I've been using Knock while it was in beta for a few months now, and was actually very impressed! Implementing notifications from scratch can be very difficult, and I was pleasantly surprised by ho...
Been using Knock for the past few months in their closed beta for SwayDM. It's been so easy to make changes to some of our more complex notification workflows. It really is a developer first platfo...
Postmark
We use Postmark to send emails and manage newsletters directly from BlogBowl. Big thanks to Postmark for their reliable API and top-notch deliverability, which makes sure your newsletters actually ...
We use Postmark not only for our emails, but also to power Ply's built-in dynamic email capabilities. It's reliable, well documented and most of all - comes with awesome human support.
Once you get familiar with Postmark's layouts and templates, the service is great for quickly creating email templates and sending them out using their simple API. The UI is simple and intuitive.
Related Comparisons
Frequently Asked Questions
Which is better, Knock or Postmark?
Based on FactScore™, Postmark leads with a score of 62.8 vs 30.1. Postmark has a higher rating of 5.0★ compared to 5.0★.
What are the pros of Knock compared to Postmark?
Knock uniquely offers: Cancelling notifications, Complex notification workflows, Developer first platform, Easy-to-use API, GUI for notification flows.
What are the pros of Postmark compared to Knock?
Postmark uniquely offers: Reliable email delivery, Fast performance, Human support, Transactional email, Affordable pricing.
Is Knock better rated than Postmark?
Knock is rated 5.0★ from 3 reviews. Postmark is rated 5.0★ from 17 reviews.
What is the FactScore™ of Knock and Postmark?
FactScore™ weighs rating and review volume together. Knock scores 30.1 and Postmark scores 62.8.
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