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Overview

This guide walks you through troubleshooting your OneSignal Web SDK setup. Before continuing, review the Web SDK setup to ensure you’ve completed all steps. The most common reasons web push appears to not be working are related to your browser and device’s notification settings:

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Browser compatibility

Users may see web permission prompts but cannot subscribe to push notifications in incognito, private, or guest browser modes.
BrowserWindowsmacOSAndroidiOS
Chrome✅✅✅✅ ¹
Firefox✅✅✅✅ ¹
Safari 10+❌✅❌✅ ¹
Microsoft Edge✅✅✅✅ ¹
Opera ²✅✅✅✅ ¹
Samsung Internet ²❌❌✅✅ ¹
Yandex ²✅✅✅✅ ¹
UC Browser ²✅❌✅✅ ¹
Internet Explorer❌❌❌❌
DuckDuckGo❌❌❌❌
¹ iOS requires web app installation (see iOS web push setup)² Chromium-based browsers appear as “Chrome” in OneSignal analytics

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Device notification settings

Device Notification Settings are the most common cause of web push not appearing on a device. Check the following settings including Focus modes (Do Not Disturb, Low Battery, etc.) before looking elsewhere.
Select the correct operating system from the tabs below. You should see Windows, macOS, Android, and iOS.
  1. Select Start > Settings > Notifications & Actions > Get notifications from apps and other senders
  2. Make sure your site and browser are also enabled.
Windows 11 Notification Settings:
  1. Select Start > Settings > System > Notifications
  1. Turn On Notifications
  2. Turn Off Do not disturb (while testing, push will show when this is disabled)
  3. Scroll down to Notifications from apps and other senders
Windows 11 Settings showing the Notifications from apps and other senders list
  1. Make sure your browsers are turned On.

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Prompt display issues

The following are common reasons why the web push notification prompt may not display as expected.
1

Confirm a prompt is configured

Review your Web permission prompt setup to ensure you have configured a prompt and understand the different browser behaviors.For instance, some browsers like Safari require a user gesture (clicking a button) before the native prompt can appear. Details for each browser can be found in our Web permission prompt > Native permission prompt section.
2

Check browser compatability, incognito, private browser, or guest browser modes.

Browsers do not allow users to subscribe to notifications in these modes. This is why the Slide Prompt may show but the native Permission Prompt will not display.Make sure you are using a browser and device that supports web push.
3

Check your browser's Notification Settings

Navigate to your browser’s settings and check the “Notifications” permission setting. Chrome example: chrome://settings/content/notifications
In this example:
  • The user has selected “Don’t allow sites to send notifications” which will prevent the native permission prompt from showing. This must show “Sites can ask to send notifications” to allow the native permission prompt to show.
  • The user has added https://yoursite.com to the “Not allowed to send notifications” list, which will prevent the native permission prompt from showing. This must be removed from the list to allow the native permission prompt to show.
Browser specific documentation:
  • Chrome - This page explains how to manage notifications in Chrome by going to Settings > Privacy and security > Site Settings > Notifications, where you can control default behavior and manage permissions for individual websites.
  • Firefox - This guide covers Firefox’s Web Push notifications, explaining how to manage notification permissions through Settings > Privacy & Security > Notifications, and how to control permissions for specific sites through the address bar’s site information icon.
  • Safari - This Apple guide explains how to customize Safari notifications on Mac through Safari > Preferences > Websites > Notifications, where you can manage which sites can send notifications and control notification behavior through System Preferences.
  • Edge - This article details how to manage Edge notifications by navigating to Settings > Privacy, search, and services > Site permissions > Notifications, or by clicking the site information icon in the address bar.
4

iOS/iPadOS requirements are not met.

For iOS, there are some additional requirements to prompt users for their subscription. More information can be seen in the Mobile Web Push for iOS/iPadOS guide.

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Troubleshooting steps

After checking the above, follow these steps to troubleshoot your OneSignal Web SDK setup.
1

Open the browser developer tools console

The browser’s developer tools let you interact with the OneSignal Web SDK and enable logging to check for errors.
  • Chrome: Right click on the page, click Inspect, and click the Console tab of the popup window that opens up.
  • Firefox: Right click on the page, click Inspect element, and click the Console tab of the popup window that opens up.
  • Safari: Go to Safari → Preferences → Advanced and make sure Show Develop menu in menu bar is checked. Then, on your webpage, right click, click Inspect element, and click the Console tab of the popup window that opens up.
Browser developer tools console open on a webpage
2

Enable web SDK logging

Run the following command in the developer tools Console:
OneSignal.Debug.setLogLevel('trace');
  • You should see undefined as the result.
  • Close the tab and open a new one to the same page. Refreshing alone won’t trigger all SDK initialization events.
  • You will start to see OneSignal SDK logs in the Console.
Browser console showing OneSignal SDK trace-level log output

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Configuration errors

You may encounter the following errors after OneSignal initializes:
Error: SDK already initialized
Console error showing SDK already initialized message
What this means: The OneSignal Web SDK init code is being called more than once, often caused by combining WordPress plugin or Shopify integration setup with manual code or accidentally adding the OneSignal init code multiple times. How to fix: Remove any duplicate init calls. If using the WordPress plugin or Shopify integration, remove any manual OneSignal code from your files.
Error: Can only be used on: (URL Set in OneSignal Dashboard)
Console error showing site origin mismatch between dashboard URL and current page
What this means: The domain you are currently visiting doesn’t match the site URL configured in your OneSignal dashboard. How to fix: Copy the site URL in your browser and paste it into your OneSignal dashboard Settings > Push & In-app > Web > Site URL configuration. Make sure it is the site origin using the following format:
  • Protocol: Must be https:// (for local testing, see Localhost configuration)
  • Domain: example.com vs www.example.com
  • Subdomain: app.example.com vs example.com
All three components must match between your actual site URL and your dashboard configuration.
Error: OneSignalSDK: The “My site is not fully HTTPS” option is no longer supported starting with version 16 (User Model) of the OneSignal SDK.
Console error showing HTTP site not supported in SDK v16
What this means: Your OneSignal dashboard is configured to use an HTTP site and you likely updated to use HTTPS. Users who subscribed while using HTTP or the “My site is not fully HTTPS” option are actually subscribed to a subdomain in the format https://your-label.os.tc, not your actual site origin. Web push is not supported on HTTP sites or websites that cannot host service workers. How to fix: Both options require your users to resubscribe because they are subscribed to the os.tc subdomain, not your site.
  1. Create a new OneSignal App and set the new App ID in your init code. This lets you continue sending push from the old app to notify users. Send notifications letting users know the site has been updated and they should resubscribe. Offering a discount or incentive helps. Set the “Launch URL” to a landing page with a resubscription prompt (Bell, Custom Link, or Category Slide). See Permission prompts for details.
  2. Keep the same App ID by using the Update an App API to update chrome_web_origin and safari_site_origin to your HTTPS origin. Because users subscribed to the os.tc subdomain, their browser does not have push permissions for your actual domain. They will be prompted again, and if they resubscribe, they will have two web push Subscriptions on the same browser — causing duplicate notifications. To prevent duplicates, delete all current web push subscribers before updating. Send a few notifications first letting users know they should resubscribe. See Permission prompts for prompt options.

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Service worker installation errors

If you are presented with the Native permission prompt and click “Allow”, you may encounter the following service worker installation errors:
Y: Registration of a Service Worker failed.
[Service Worker Installation] Installing service worker failed TypeError: Failed to register a ServiceWorker for scope (‘https://your-site.com/’) with script (‘https://your-site.com/...’): A bad HTTP response code (404) was received when fetching the script.
[Service Worker Installation] Installing service worker failed TypeError: Failed to register a ServiceWorker for scope (‘https://www.yoursite.com/’) with script (‘https://www.yoursite.com/...’): A bad HTTP response code (403) was received when fetching the script.
Console error showing service worker registration failure with 404 or 403 response
The script has an unsupported MIME type (‘current MIME type’). [Service Worker Installation] Installing service worker failed SecurityError: Failed to register a ServiceWorker for scope (‘https://your-site.com/’) with script (‘https://your-site.com/…’): The script has an unsupported MIME type (‘current MIME type’).
Console error showing unsupported MIME type for service worker script
[Service Worker Installation] Installing service worker failed SecurityError: Failed to register a ServiceWorker for scope (‘https://your-site.com/’) with script (‘https://your-site.com/…’): The script resource is behind a redirect, which is disallowed.
Console error showing service worker script blocked by a redirect
What this means: Your service worker file is configured incorrectly. How to fix:
1

Find your service worker path

The SDK looks for the OneSignalSDKWorker.js service worker file in the root directory of your site unless you specify a custom filename or location as described in the Service Worker setup guide.Make sure you have configured the correct filename, location, and scope for the SDK to find the service worker file.
2

Visit the service worker file directly in your browser

Based on your configuration, open the file directly in your browser.
  • If you did not configure a custom location, then you should see the JavaScript code for the service worker file in your site’s root: https://yoursite.com/OneSignalSDKWorker.js
  • If using WordPress, you should see it here: https://yoursite.com/wp-content/plugins/onesignal-free-web-push-notifications/sdk_files/OneSignalSDKWorker.js
  • If using a custom location, you should see it here: https://yoursite.com/your-custom-location/OneSignalSDKWorker.js
File names are case-sensitive. Make sure you use OneSignalSDKWorker.js or the filename you configured.Some servers will automatically lowercase the filename. Take this into consideration if you cannot find the file.
3

Verify the file loads

  • You should see the following JavaScript code:
    JavaScript
    importScripts("https://cdn.onesignal.com/sdks/web/v16/OneSignalSDK.sw.js");
  • This file must be served with a content-type of application/javascript.
  • There can be no redirects to this file. Files must be hosted on the same domain as your site (no CDN or proxy domains).
See the Service Worker setup guide for more detailed setup instructions.

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Notifications not shown

This section assumes:
  1. You have reviewed the Notifications not shown: Web Push guide for common reasons why notifications may not be showing up on your device.
  2. You were shown the Native permission prompt and clicked “Allow”. See Prompt display issues above if you did not subscribe via the Native permission prompt.
If the above are true, follow these steps to check your Subscription ID and send yourself a push notification:
1

Get your Subscription ID

Run the following code in the browser developer tools console:
JavaScript
function getUserInfo() {
  console.log('getUserInfo()');
  Promise.all([
    OneSignal.Notifications.isPushSupported(),
    OneSignal.Notifications.permission,
    OneSignal.User.PushSubscription.optedIn,
    OneSignal.User.PushSubscription.id
  ]).then(([
    isPushSupported,
    isSubscribed,
    isOptedIn,
    subscriptionId
  ]) => {
    console.log('The current URL of this page: ', location.href);
    console.log('Push is supported on this browser: ', isPushSupported);
    console.log('You are subscribed to notifications in the browser: ', isSubscribed);
    console.log('You are opted-in with OneSignal: ' , isOptedIn);
    console.log('Your OneSignal Subscription ID: ', subscriptionId);
  }).catch(e => {
    console.error('Error getting user info:', e);
  });
}
getUserInfo();
This will tell you:
  • The URL of the page you are on if there is any confusion.
  • If the current browser supports push notifications.
    • true means the browser supports push notifications.
    • false means the browser does not support push notifications.
  • If you are subscribed to notifications in the browser.
    • true means you allowed push permissions for this URL.
    • false means you did not allow or denied push permissions for this URL.
  • If you are opted-in with OneSignal.
    • true means your Subscription is subscribed to push notifications in OneSignal.
    • false means your Subscription is not subscribed to push notifications in OneSignal. Check if the optOut() method is being called on your site.
  • Your OneSignal Subscription ID.
    • Save this for the next step. This is the ID you will use to send yourself a push notification.
    Console output showing push support status, subscription state, and Subscription ID
    Save this console data to a text file and share with OneSignal Support if you need further assistance.
2

Send yourself a notification

If you are subscribed to notifications, opted-in with OneSignal, and have a Subscription ID, you can send yourself a notification.Follow the steps in Test subscriptions to set yourself as a tester and send yourself a notification.
3

Test with Chrome

If you are not getting notifications in Chrome, use these Chrome-specific diagnostic tools to identify the issue.
  1. In a new tab, open chrome://gcm-internals.
  2. Click the “Start Recording” button on the top left. Making sure you see “Connection State: CONNECTED”.
  3. Leave this open and send yourself another push notification to your Chrome web push Subscription.
  4. You should see something in the “Receive Message Log” if you got it.
Chrome GCM internals page showing Receive Message Log with a received data message
  • If you don’t see a “Data msg received”, then your Chrome browser is not receiving the notification at all. Contact OneSignal Support with the GCM internals logs.
  • If you see “Data msg received” but you still didn’t receive a notification, continue to the next step.
  1. Open a new tab to chrome://serviceworker-internals
  2. Search for Scope: https://your-site.com (replace your-site.com with your actual site domain).
  3. Click Inspect, or Start -> Inspect. A Chrome Developer Tools popup will appear.
Chrome service worker internals page showing the Inspect button for a registered service worker
  1. On the Chrome Developer Tools popup to our service worker, click the Console tab, and run OneSignalWorker.log.trace();. It should return undefined. Any messages from our service worker should now appear in this popup.
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!

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FAQ

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Why do I see “SDK already initialized”?

The OneSignal Web SDK init code is being called more than once on the page. This commonly happens when combining the WordPress plugin with manual code, or when the init tag is included in multiple page templates. Remove duplicate init calls to resolve it.

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Can I use web push on HTTP sites?

No. Web push requires HTTPS because service workers — which handle push delivery — only work on secure origins. If you previously used the “My site is not fully HTTPS” option, you must migrate to HTTPS. See Configuration errors for migration steps.

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How do I test web push on localhost?

You can test on localhost during development. See Localhost configuration for setup instructions. Note that localhost testing only works in Chromium-based browsers.

Web SDK setup

Complete the initial OneSignal Web SDK installation and configuration.

Service worker setup

Configure the OneSignal service worker file for your site.

Permission prompts

Configure how and when to prompt visitors for web push permission.

Notifications not shown

Common reasons why web push notifications may not appear on your device.