Postmark vs Stream
On the evidence we track, Stream leads this comparison with a composite score of 80/100. Scores are only directly comparable because these tools share a category; the full breakdown and every source is below.
Capabilities
Feature-by-feature on the axes that matter for communication apis. “-” means undocumented, not absent.
What each one is
The product in its own terms, so the numbers below have context.
Postmark
Postmark is a transactional email service that connects with popular CMS platforms, marketing automation tools, forms providers, and business applications to send reliable emails across your workflows.
Stream
LeaderStream provides developer-friendly APIs and pre-built SDKs that integrate chat, live video, activity feeds, and automated content moderation into applications, allowing developers to add complex real-time features without building infrastructure from scratch.
Pricing
List pricing as published by each vendor, with the date we read it. Always verify at the source before you buy.
Postmark
From $15/mo. Free tier with 100 emails/month. Pay-as-you-go overages starting at $1.80 per 1,000 emails.
- FreeFree
- 100 emails/month
- REST API
- SMTP
- Transactional email
- Sandbox Mode
- +3 more
- Basic$15/mo + $1.80 per 1,000 overage emails
- 10,000+ emails/month
- Industry-leading deliverability
- 45-day retention
- 5 custom domains
- Unlimited emails/day
- +3 more
- Pro$16.50/mo + $1.30 per 1,000 overage emails
- 10,000+ emails/month
- Industry-leading deliverability
- Customizable retention up to 365 days
- 10 custom domains
- Unlimited emails/day
- +5 more
- Platform$18/mo + $1.20 per 1,000 overage emails
- 10,000+ emails/month
- Industry-leading deliverability
- Customizable retention up to 365 days
- Unlimited custom domains
- Unlimited emails/day
- +5 more
Stream
LeaderFrom $499/month. Free tier for makers. Usage-based overage charges.
- BuildFree
- REST API
- SDKs (Node, Python, Ruby, PHP)
- Webhooks
- Customizable UI
- Flat & Timeline Feeds
- +3 more
- Start$499/month (annual commitment) or $599/month (monthly). Overages: $25 per 1k activities, $9 per 10k API calls
- Ranked Feeds
- Ticketed Support
- Dedicated Regional Servers
- HIPAA
- 2FA
- +3 more
- Elevate$899/month (annual commitment) or $999/month (monthly). Overages: $23 per 1k activities, $9 per 10k API calls
- All Start features
- EnterpriseContact sales
- 99.999% SLA
- SAML/SSO
- Private Dedicated Servers
- 24/7 Support
- Activity-based pricing
- +1 more
Platform & deployment
Where each product runs and how it can be hosted. A dash means undocumented, not unsupported.
Integrations
What each product connects to. Counts come from the vendor's own integration directory where one exists.
- Slack
Postmark
- Mailcoach
- Datadog
- Craft CMS
- Customer.io
- ActiveCampaign
- Supabase
- Bubble
- Figma
- Google Sheets
- Gravity Forms
- Gravity SMTP for WordPress
- Netlify
- Stripe
- Stripo
- Typeform
- WordPress
- WP Mail SMTP
- Zapier
- Tabular
- SureTriggers
- Marka Email Generator
Stream
Leader- Jenkins
- GitHub
- Postman
- Xcode
- Android Studio
- React
- React Native
- Flutter
- Swift
- SwiftUI
- Kotlin
- Jetpack Compose
- Expo
- Vercel AI SDK
Postmark or Stream: which one depends on you
A composite score cannot know your constraints. Describe them and both get re-weighted against what you actually need, with the evidence behind every position.
Free to run, no account needed to start. How the evaluation works
Comparison generated from independently-sourced facts. Every value links to its source and retrieval date. See the method.