Firebase Cloud Messaging (FCM) is Google’s free delivery service for push: your server hands it a message and it carries it to Android, iOS and web devices. OneSignal is an engagement platform that runs on top of it. It sends Android push through your Firebase project and adds a dashboard where marketers target, schedule and test messages, billed by monthly active users.
Where OneSignal and FCM differ
Short answer
| If you need | Choose |
|---|---|
| Push is your only channel and your server already decides what to send |  FCM |
| You want no per-user or per-message bill at any volume | FCM |
| The app already runs on Firebase and campaigns target Google Analytics audiences | FCM |
| Marketers need to write, schedule and test push without an engineer |  OneSignal |
| The same users also need email, SMS or in-app messages | OneSignal |
| You want delivery stats per message without querying BigQuery | OneSignal |
| Your product needs notifications that batch and follow each user’s channel choices on their own |  SuprSend, sending Android push through FCM |
Need a deeper, more automated notification system than push tools give? Choose SuprSend
SuprSend is an agentic notification platform for product alerts and customer engagement messages, across email, SMS, push, WhatsApp, Slack, Microsoft Teams and an in-app inbox, with tenants, translations and preferences built in. Its workflows batch events into digests and check each user’s channel choice per category, with every step logged. AI agents build and change them, and Android push still goes out through your Firebase project. OneSignal runs campaigns; FCM delivers what your server sends.
| SuprSend | OneSignal | FCM | |
|---|---|---|---|
| Channels from one trigger | Email, SMS, push, WhatsApp, Slack, Teams, in-app | Push, email, SMS and RCS, in-app | Push |
| Digest of product events | Batch and digest steps, from Business | No | No |
| User preferences | Per category, across channels | Push categories | Topic subscriptions |
| What AI agents can do | Build and change workflows, templates and tenants, test and send, and query logs and analytics | Send; manage users, segments and templates | Send one message |
| G2 rating | 4.8 from 129 reviews | 4.7 from 1,237 reviews | - |
| G2 ease of setup | 9.4 from 72 reviews | 8.9 from 554 reviews | - |
Feature by feature
From OneSignal’s pricing page, Firebase’s pricing page and both documentation sites, September 2026. Where a feature depends on the plan, the cell names the plan.
Basics
| Capability | OneSignal | FCM |
|---|---|---|
| What it is | Engagement platform with a dashboard for push, email, SMS and in-app messages | Google’s push delivery service, part of Firebase |
| Billing unit | Platform fee plus mobile MAU, web push subscribers, email and SMS sends | None; Cloud Messaging is free |
| Free use | Mobile push and in-app up to 1,000 MAU; 10,000 emails a month | Unlimited messages; 600,000 a minute by default |
| Who sends messages | Marketers in the dashboard; developers through the REST API | Developers from their own server; marketers in the Notifications composer |
Channels
| Capability | OneSignal | FCM |
|---|---|---|
| Android push | YESThrough your Firebase project | YES |
| iOS push | YESStraight to APNs | YESHanded to APNs |
| Web push | YES$0.004 per subscriber on Growth | YES |
| YESShared IP; dedicated IP on annual plans by volume | NO | |
| SMS and RCS | YESBilled per send | NO |
| In-app messages | YESIncluded with mobile push | YESIn-App Messaging: card, modal, image and banner layouts |
| iOS Live Activities | YESIncluded with mobile push | YESUpdates sent as an FCM message |
Targeting and automation
| Capability | OneSignal | FCM |
|---|---|---|
| Audiences | Segments on data tags and behaviour: 6, 10, 20 or unlimited by plan | Topics, Google Analytics audiences, app version and language |
| Multi-step flows | Journeys with branching and cross-channel steps: 3, 5, 20 or unlimited active by plan | None; a composer campaign is one message to one audience |
| Send in the user’s timezone | YESTimezone delivery on every plan | YES, BUTComposer campaigns only |
| A/B testing | YESStandard on Free and Growth; multivariate on Professional | YESFirebase A/B Testing on composer and in-app campaigns |
| Preferences | Push categories through the opt-in prompt | Topic subscriptions your app manages |
Developers and agents
| Capability | OneSignal | FCM |
|---|---|---|
| User and device records | Users with an external ID; each device is a subscription on the user | Registration tokens, mapped to users in your own database |
| Sending API | REST API; unlimited sends on every plan | HTTP v1 API and Admin SDK; 240 messages a minute to one Android device |
| Client SDKs | Android, iOS, web, React Native, Flutter, Unity, .NET MAUI, Cordova; Huawei and Amazon devices | Android, iOS, web, Flutter, Unity, C++ |
| Delivery data | Per-message stats; confirmed receipt from Growth; 30 or 90 days of reports below Professional | Composer reports; per-message data through a BigQuery export |
| MCP server | Hosted, with OAuth: users, segments, templates, sends and exports | Firebase MCP server sends a message to a token or topic |
Pricing
A worked example for an app with 20,000 mobile monthly active users sending push only: OneSignal Growth is $19 plus $240 for mobile MAU, $259 a month, with in-app messages included. The same sends through FCM cost nothing, and the server that stores tokens, schedules and retries is yours to run.
| Capability | OneSignal | FCM |
|---|---|---|
| Entry plan | Free, up to 1,000 mobile MAU | Free, with no plan to buy |
| First paid plan | Growth from $19 a month, month to month | None for Cloud Messaging |
| Mobile push | $0.012 per MAU on Growth | Free at any volume |
FAQ
Is OneSignal better than Firebase Cloud Messaging?
OneSignalOneSignal is better for a team that wants marketers to segment, schedule and test push from a dashboard, and to reach the same users by email, SMS and in-app messages, on published month-to-month pricing.
FCMFCM is better for developers who want free delivery at any volume, full control of the payload from their own server, and a push service that sits inside an app already built on Firebase.
Which is cheaper, OneSignal or FCM?
Firebase charges nothing for Cloud Messaging at any volume. OneSignal is free below 1,000 mobile monthly active users; Growth then costs $19 a month plus $0.012 per mobile MAU, with email, SMS and web push priced separately. On the bill FCM is always cheaper. What you pay for instead is the engineering time for token storage, scheduling, retries and reporting, and any Cloud Functions or Firestore usage behind it.
What moves when switching from FCM to OneSignal?
The Firebase project stays: you upload its service account to OneSignal, which keeps sending Android push through it. The app adds the OneSignal SDK and drops its own Firebase message handling, existing users are imported through the API with their external IDs, topics become segments or data tags, and composer campaigns are rebuilt as OneSignal messages or Journeys. OneSignal publishes a migration guide.
Can I use OneSignal and FCM together?
Yes, and every OneSignal send to an Android app from Google Play already goes through FCM. If the app also keeps its own Firebase messaging code, that code has to pass OneSignal payloads to the OneSignal SDK and leave token calls such as getToken and deleteToken alone, or users see duplicate or missing notifications.
What if we need more than a push tool gives?
SuprSend, which publishes this page, runs push, email, SMS, WhatsApp and Slack from one workflow, and sends Android push through your Firebase project.