OneSignal vs Postmark Comparison
Compare OneSignal vs Postmark features, pricing, and more.
Last updated: November 2026
OneSignal
7.1/10
OneSignal is a customer messaging platform for sending mobile push, web push, in-app messages, email and SMS to app and website users.
Postmark
6.1/10
Postmark is an email delivery API and SMTP service, owned by ActiveCampaign, that sends transactional and broadcast email for software products and web apps.
Feature-by-Feature Comparison
| Feature | | |
|---|---|---|
| Scores | ||
| Overall Rating | 7.1/10 | 6.1/10 |
| Scalability | 8/10 | 7/10 |
| Ease of Use | 8/10 | 7/10 |
| Customization | 6/10 | 5/10 |
| Security | 7/10 | 6/10 |
| Support | 6/10 | 6/10 |
| Cost | 7/10 | 6/10 |
| Integration | 8/10 | 6/10 |
| Analytics | 6/10 | 6/10 |
| Pricing | ||
| Free plan | Yes | Yes |
| Cheapest paid plan | $19/mo Growth | $15/mo Basic |
| Estimated cost for 10 users | Free Free | Free Free |
| Features | ||
| SMS Marketing | ||
| Email Marketing | ||
| Segmentation | ||
| A/B Testing | ||
| Landing Pages | Not listed | |
| Webinars | Not listed | |
Which One Should You Choose?
Why choose OneSignal
- Higher Integration score (8/10 vs 6/10)
- Higher Scalability score (8/10 vs 7/10)
- Better fit for marketing teams (7/10 vs 2/10)
- Includes SMS Marketing, which Postmark lacks
- Includes Segmentation, which Postmark lacks
Why choose Postmark
Our data shows no clear advantage over OneSignal.
Pros & Cons
OneSignal
Pros
- A free plan with unlimited push up to 1,000 MAU and 10,000 emails a month makes it cheap to start.
- Push, in-app, email and SMS run from one platform with cross-channel journeys.
- Reviewers on G2 and PeerSpot say the dashboard is easy for non-technical marketers to use.
- A broad integration catalog covers CDPs such as Segment, RudderStack and Hightouch, data warehouses, and analytics tools.
Cons
- PeerSpot reviewers call it expensive for large subscriber bases.
- Free and Growth plans cap segments at 6 and 10, and reporting history at 30 and 90 days.
- SMS pricing is not published and requires a sales conversation.
- Reviewers mention unclear documentation for advanced cases and limited in-app design options.
Postmark
Pros
- Separate transactional and broadcast streams run on separate IPs, which protects deliverability for critical app email.
- A free plan of 100 emails a month never expires, so developers can test the integration at no cost.
- Clear volume pricing with no fees for broadcast messages; the Platform plan adds unlimited domains, users and servers for $18 a month.
- Offers both a REST API and SMTP, plus inbound email processing on the Pro plan and above.
- Many Capterra reviewers praise its speed and deliverability, with a 4.7 rating.
Cons
- Not a marketing platform: it has no list uploads, visual editor or campaign reporting.
- Billed monthly only, with no PayPal or purchase order payments.
- Some reviewers report slow support and accounts paused during approval reviews since the ActiveCampaign acquisition.
- Per-email costs are higher than bulk services such as Amazon SES at high volumes.
- Nothing sits between the 100-email free plan and the 10,000-email paid plans.
