Postmark vs Firebase
Reliable transactional email with fast delivery
vs. Google's mobile & web app development platform
Pricing tiers
Postmark
Free
100 emails/month forever. No credit card. Side projects and testing.
Free
Basic — 10k
10,000 emails/month. Overage $1.80/1k. Unlimited emails/day.
$15/mo
Pro — 10k
10,000 emails/month. Overage $1.30/1k. Inbound email + message streams.
$17/mo
Platform — 10k
10,000 emails/month. Overage $1.20/1k. Team collab, more domains.
$18/mo
Enterprise (>1.5M)
Custom for senders exceeding 1.5M/month.
Custom
Firebase
Spark (No-cost)
Free tier with generous quotas. No credit card required. Cannot exceed free quotas.
Free
Blaze (Pay as you go)
Usage-based billing. Includes Spark quotas free, then pay Google Cloud rates. Required for Cloud Functions outbound networking, scheduled jobs, some extensions.
Custom
Free-tier quotas head-to-head
Comparing free on Postmark vs spark on Firebase.
| Metric | Postmark | Firebase |
|---|---|---|
| auth mau | — | 50000 users/month |
| firestore deletes per day | — | 20000 docs/day |
| firestore egress gib month | — | 10 GiB/month |
| firestore reads per day | — | 50000 docs/day |
| firestore storage gib | — | 1 GiB |
| firestore writes per day | — | 20000 docs/day |
| functions cpu seconds | — | 200000 CPU-sec/month |
| functions gb seconds | — | 400000 GB-sec/month |
| functions invocations | — | 2000000 invocations/mo |
| functions outbound gb | — | 5 GB/month |
| hosting storage gb | — | 10 GB |
| hosting transfer gb month | — | 10.8 GB/month |
| phone sms verifications day | — | 10 sms/day |
| rtdb connections | — | 100 connections |
| rtdb downloaded gb month | — | 10 GB/month |
| rtdb stored gb | — | 1 GB |
| storage downloaded gb day | — | 1 GB/day |
| storage gb | — | 5 GB |
| storage operations day | — | 50000 ops/day |
Features
Postmark · 12 features
- Activity Search — Full-text search over sent messages for 45-365 days.
- Bounce Handling — Automatic hard/soft bounce detection + suppression management.
- Broadcast Messages — Via separate Broadcast Message Stream. Bulk sends with throttling.
- DKIM + SPF — One-click verification + auto-renewal of DKIM keys.
- Inbound Email — Route inbound emails to your webhook. Parse attachments, threads.
- Message Streams — Isolate transactional from marketing for separate deliverability reputation.
- Open + Click Tracking — Configurable at template or send level.
- Raw API Access — 100+ endpoints for bounces, servers, tags, templates, stats.
- Servers — Multi-tenant isolation: each "server" has its own API token + reputation.
- Templates — Mustachio template language with variables, alias + versioning.
- Transactional Send — Reliable API for password resets, receipts, notifications. Sub-10s delivery.
- Webhook Events — Delivery, bounce, spam complaint, open, click, subscription change.
Firebase · 20 features
- A/B Testing — Experiments on Remote Config params, FCM notifications, and Analytics events. Ba…
- App Check — Attestation service: only requests from authentic, untampered app instances reac…
- App Hosting — Managed hosting for modern web apps (Next.js, Angular, SvelteKit). Git-based dep…
- Cloud Firestore — Serverless NoSQL document database. Real-time sync, ACID transactions, offline p…
- Cloud Functions — Serverless functions (Node.js/Python). Trigger on HTTP, Firestore, RTDB, Auth, S…
- Cloud Storage — Object storage for user files. Built on GCS. Security rules + signed URLs. Resum…
- Crashlytics — Real-time crash reporting for iOS/Android/Unity/Flutter. Stack traces, breadcrum…
- Data Connect — GraphQL API backed by Cloud SQL for PostgreSQL. Type-safe SDK generation. Previe…
- Dynamic Links — Deep links that survive app install. NOTE: deprecated, shutdown Aug 2025 — migra…
- FCM Topics — Publish/subscribe messaging: devices subscribe to topic names; backend sends one…
- Firebase AI Logic — Client-side SDK to call Gemini models directly from mobile/web. Formerly "Vertex…
- Firebase Authentication — Drop-in auth: email/password, phone, anonymous, 10+ federated providers, custom …
- Firebase Cloud Messaging — Push notifications for iOS, Android, Web (APNs/FCM transports). Topics, device g…
- Firebase Extensions — Pre-packaged Cloud Functions + config: Stripe, Algolia search, image resize, tra…
- Firebase Hosting — Static + dynamic hosting with global CDN. Preview channels, atomic deploys, rewr…
- Genkit — Open-source AI app framework. Unified API for Gemini, OpenAI, Ollama; tools, RAG…
- Google Analytics for Firebase — Free unlimited event tracking with audience building. BigQuery export on Blaze. …
- Performance Monitoring — App startup, HTTP network, and custom traces. Integrates with Google Analytics e…
- Realtime Database — Low-latency JSON tree database with WebSocket sync. Best for high-frequency pres…
- Remote Config — Feature flags / parameterized config with conditional targeting (user property, …
Developer interfaces
| Kind | Postmark | Firebase |
|---|---|---|
| CLI | — | Firebase CLI |
| SDK | postmark-dotnet, postmarker (Python), postmark-go, postmark (Node), postmark-php, postmark-rails | Admin SDK (Go), Admin SDK (Java), Admin SDK (Node.js), Admin SDK (Python), Android SDK, Apple Platforms SDK, Flutter SDK (FlutterFire), JavaScript SDK, Unity SDK |
| REST | Postmark REST API | Auth REST API, Cloud Storage REST, Firebase Management API, Firestore REST API, Realtime Database REST |
| MCP | — | Firebase MCP Server |
| OTHER | Inbound Email, SMTP Relay, Webhooks | Firestore gRPC, Realtime Database WebSocket |
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