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Overview

This guide explains how to integrate OneSignal push notifications into a ReactJS or NextJS application. It covers everything from installation to configuration and service worker management.

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Requirements

  • Configured OneSignal app and platform. See Web Push Setup to get started.

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Installation

Choose your preferred package manager: 
yarn add react-onesignal

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Initialization

Import the OneSignal service and initialize it in your root component. Replace YOUR_APP_ID with your OneSignal app ID found in Keys & IDs. 
"use client";

import { useEffect } from 'react';
import OneSignal from 'react-onesignal';

export default function Page() {
  useEffect(() => {
    // Ensure this code runs only on the client side
    if (typeof window !== 'undefined') {
      OneSignal.init({
        appId: 'YOUR_APP_ID',
        // You can add other initialization options here
        notifyButton: {
          enable: true,
        }
      });
    }
  }, []);

  return (
    <div>
      <h1>Hello, world!</h1>
      {/* Rest of your page content */}
    </div>
  );
}

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Customizing init options

You can customize your initialization with additional init parameters.

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Service Worker Settings

If you haven’t done so already, you will need to download the OneSignal Service Worker file to add to your site. The OneSignalSDKWorker.js file must be publicly accessible. You can put it in your public directory, top-level root, or a subdirectory. However, if you are placing the file in a subdirectory and/or have another service worker for your site, then make sure to specify the path. See OneSignal Service Worker for details.
OptionDescription
serviceWorkerParamScope controlled by the OneSignal worker. Recommendation: Use a custom sub-path (e.g., "/onesignal/").
serviceWorkerPathPath to your hosted OneSignal service worker file (e.g., "onesignal/OneSignalSDKWorker.js"). Must be publicly accessible.
See a full working example here: React + OneSignal Example

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Hosting the worker

  • Public root (default): /OneSignalSDKWorker.js
  • Custom folder (recommended): e.g., /onesignal/OneSignalSDKWorker.js as set in the previous step.

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Verify service worker hosting

Visit the path in your browser to confirm it’s accessible. If you used root: 
https://your-site.com/OneSignalSDKWorker.js
If using the example path: 
https://your-site.com/onesignal/OneSignalSDKWorker.js
It should return valid JavaScript.

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Important notes

  • Avoid Duplicate Initialization in Development
    • When testing in a development environment, you might see the OneSignal SDK initialize twice, which can cause console errors.
    • This happens due to <React.StrictMode> causing effects to run twice in development. To resolve it, remove <React.StrictMode> from your root component during development.
Strict mode only affects development—it does not impact production builds.

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Testing the OneSignal SDK integration

This guide helps you verify that your OneSignal SDK integration is working correctly by testing push notifications and subscription registration.

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Check web push subscriptions

1

Launch your site on a test device.

  • Use Chrome, Firefox, Edge, or Safari while testing.
  • Do not use Incognito or private browsing mode. Users cannot subscribe to push notifications in these modes.
  • The prompts should appear based on your permission prompts configuration.
  • Click Allow on the native prompt to subscribe to push notifications.

Web push native permission prompt

2

Check your OneSignal dashboard

Check the OneSignal dashboard:
  • Go to Audience > Subscriptions.
  • You should see a new entry with the status Subscribed.

Dashboard showing subscription with 'Subscribed' status

You have successfully created a web push subscription. Web push subscriptions are created when users first subscribe to push notifications on your site.

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Set up test subscriptions

Test subscriptions are helpful for testing a push notification before sending a message.
1

Add to Test Subscriptions.

In the dashboard, next to the subscription, click the Options (three dots) button and select Add to Test Subscriptions.

Adding a device to Test Subscriptions

2

Name your subscription.

Name the subscription so you can easily identify your device later in the Test Subscriptions tab.

Dashboard showing the 'Name your subscription' field

3

Create a test users segment.

Go to Audience > Segments > New Segment.
4

Name the segment.

Name the segment Test Users (the name is important because it will be used later).
5

Add the Test Users filter and click Create Segment.

Creating a 'Test Users' segment with the Test Users filter

You have successfully created a segment of test users. We can now test sending messages to this individual device and groups of test users.

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Send test push via API

1

Get your App API Key and App ID.

In your OneSignal dashboard, go to Settings > Keys & IDs.
2

Update the provided code.

Replace YOUR_APP_API_KEY and YOUR_APP_ID in the code below with your actual keys. This code uses the Test Users segment we created earlier.
curl -X \
POST --url 'https://api.onesignal.com/notifications' \
 --header 'content-type: application/json; charset=utf-8' \
 --header 'authorization: Key YOUR_APP_API_KEY' \
 --data \
 '{
  "app_id": "YOUR_APP_ID",
  "target_channel": "push",
  "name": "Testing basic setup",
  "headings": {
  	"en": "👋"
  },
  "contents": {
    "en": "Hello world!"
  },
  "included_segments": [
    "Test Users"
  ],
  "chrome_web_image": "https://avatars.githubusercontent.com/u/11823027?s=200&v=4"
}'
3

Run the code.

Run the code in your terminal.
4

Check images and confirmed delivery.

If all setup steps were completed successfully, the test subscriptions should receive a notification.
Only Chrome supports images. Images will appear small in the collapsed notification view. Expand the notification to see the full image.

Expanded push notification with image on Chrome macOS

5

Check for confirmed delivery.

In your dashboard, go to Delivery > Sent Messages, then click the message to view stats.You should see the confirmed stat, meaning the device received the push.
Safari does not support Confirmed Delivery.

Delivery stats showing confirmed delivery

If you’re on a Professional plan or higher, scroll to Audience Activity to see subscription-level confirmation:

Confirmed delivery at the device level in Audience Activity

You have successfully sent a notification via our API to a segment.
Need help? Contact support@onesignal.com with the following information:
  • Copy-paste the API request and response into a .txt file
  • Your Subscription ID
  • Your website URL with the OneSignal code
We’ll be happy to help!

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User identification

Previously, we demonstrated how to create web push Subscriptions. Now we’ll expand to identifying Users across all their subscriptions (including push, email, and SMS) using the OneSignal SDK. We’ll cover External IDs, tags, multi-channel subscriptions, privacy, and event tracking to help you unify and engage users across platforms.

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Assign External ID

Use an External ID to identify users consistently across devices, email addresses, and phone numbers using your backend’s user identifier. This ensures your messaging stays unified across channels and 3rd party systems (especially important for Integrations). Set the External ID with our SDK’s login method each time they are identified by your app.
OneSignal generates unique read-only IDs for subscriptions (Subscription ID) and users (OneSignal ID).As users download your app on different devices, subscribe to your website, and/or provide you email addresses and phone numbers outside of your app, new subscriptions will be created.Setting the External ID via our SDK is highly recommended to identify users across all their subscriptions, regardless of how they are created.

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Add data tags

Tags are key-value pairs of string data you can use to store user properties (like username, role, or preferences) and events (like purchase_date, game_level, or user interactions). Tags power advanced Message Personalization and Segmentation allowing for more advanced use cases. Set tags with our SDK addTag and addTags methods as events occur in your app. In this example, the user reached level 6 identifiable by the tag called current_level set to a value of 6.

A user profile in OneSignal with a tag called "current_level" set to "6"

We can create a segment of users that have a level of between 5 and 10, and use that to send targeted and personalized messages:

Segment editor showing a segment targeting users with a current_level value of greater than 4 and less than 10


Screenshot showing a push notification targeting the Level 5-10 segment with a personalized message

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Add email and/or SMS subscriptions

Earlier we saw how our SDK creates web push subscriptions to send push. You can also reach users through emails and SMS channels by creating the corresponding subscriptions. If the email address and/or phone number already exist in the OneSignal app, the SDK will add it to the existing user, it will not create duplicates. You can view unified users via Audience > Users in the dashboard or with the View user API.

A user profile with push, email, and SMS subscriptions unified by External ID

Best practices for multi-channel communication
  • Obtain explicit consent before adding email or SMS subscriptions.
  • Explain the benefits of each communication channel to users.
  • Provide channel preferences so users can select which channels they prefer.
To control when OneSignal collects user data, use the SDK’s consent gating methods: See our Privacy & security docs for more on:

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Listen to push, user, and in-app events

Use SDK listeners to react to user actions and state changes. The SDK provides several event listeners for you to hook into. See our SDK reference guide for more details.

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Push notification events

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User state changes

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Advanced setup & capabilities

Explore more capabilities to enhance your integration:

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Web SDK setup & reference

Make sure you’ve enabled all key features by reviewing the Web push setup guide. For full details on available methods and configuration options, visit the Web SDK reference.
Congratulations! You’ve successfully completed the Web SDK setup guide.
Need help?Chat with our Support team or email support@onesignal.comPlease include:
  • Details of the issue you’re experiencing and steps to reproduce if available
  • Your OneSignal App ID
  • The External ID or Subscription ID if applicable
  • The URL to the message you tested in the OneSignal Dashboard if applicable
  • Any relevant logs or error messages
We’re happy to help!