Audience > All Users

OneSignal automatically creates a device/channel record with unique OneSignal User ID aka player_id when:

• a user opens your mobile app for the first time
• a user subscribes to your website with the OneSignal SDK initialized
• an email address is provided. See Import Email Addresses
• a phone number is provided. See SMS Overview

For example, if a user subscribes to your website and provides you their email, then downloads and opens your mobile app, they will have 3 player_id records within OneSignal: a web push record, an email record and a mobile push record.

It is recommended to combine your OneSignal User Record player_ids through your own custom User ID called external_user_id. See the Database, DMP, & CRM Integration guide for more details.

Subscription Process

OneSignal automatically tracks subscription and certain device data through the SDK (see: Data Collected by the OneSignal SDK. You can view this data through the Dashboard and even Export User Data through the dashboard or API.

If you have an analytics tool, see our Analytics Integration Guides for more details on setting this up.

Push Notification and In-App Message Channel Opt-in

Web Push Subscribers and iOS Mobile App Subscribers must opt-in to subscribe. See our Prompting Guide for more details on getting permission.

Android Mobile App Subscribers are opted-in when they open the app for the first time.

OneSignal's SDKs provide Permission Observer and Subscription Observer methods to detect these events client side.

Email Opt-in

Email records subscribe when added to OneSignal. See Import Email Addresses.

SMS Opt-in

SMS Phone records subscribe when added to OneSignal. See Import Phone Numbers.

Detecting Unsubscribes

Push Notifications Opt-out

Push records get unsubscribed when they:

• Uninstall the mobile App
• Clear Browser Data
• Go into Device or Browser settings and unsubscribe (see Unsubscribe from Notifications Guide)
• You unsubscribe them through the SDK method to disable push or API Edit device call, setting notification_types to -2.

Any subscribed device that unsubscribes will be detected and marked in OneSignal automatically when they:

1. Interact with the OneSignal SDK (increasing Revoked Count). You can capture this event with our Subscription Observer methods and send to your Database.

2. After you send 2 notifications to the unsubscribed device on Android Mobile Apps and Web. For iOS, this may take a week for Apple to update the subscription record. More details below.

If you target devices directly via the API using include_player_ids or include_external_user_ids parameters we also provide the unsubscribed devices as "invalid_player_ids" or "invalid_external_user_ids" callback results which you can process in your Internal Database, DMP, & CRM.

Email Opt-out

Email records get unsubscribed when users click unsubscribe url.

SMS Opt-out

SMS records get unsubscribed when users reply "STOP" or your opt-out keyword to the sending number. Twilio then marks the device as unsubscribed. Upon the next SMS sent to the device, Twilio responds with an Error Code 21610 at which point we mark the device unsubscribed in our system.

It is a good practice to include an opt-out sentence in your SMS such as: "Reply STOP to unsubscribed" or "Reply STOP to stop future messages".

Revoked Count

This tracks how many previously subscribed devices returned to your app after opting-out of push permissions and how many web push users opted-out of push using the SDK.

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iOS Unsubscribe Detection

Apple changed the way it reports unsubscribe events on iOS apps.

In the past, they would report the unsubscribed device upon the 2nd notification. They stopped doing this for privacy reasons. Apple intentionally does not want token invalidation to be used as a method to detect app uninstall.

Some details provided by Apple can be found here: https://forums.developer.apple.com/thread/116445

Currently if a device unsubscribes and opens the app, we detect this right away through our SDK. However if the device uninstalls the app or unsubscribes and does not open the app, it may take several weeks for Apple to report the device unsubscribe event.

If you need to remove older devices, you can delete them using our dashboard or API.

Resubscribing Users

If a device was unsubscribed, how do they resubscribe?

Push Notifications Resubscribe

Web Push Device Records will get prompted again if they unsubscribe through the browser settings and will be resubscribed when the following occurs:

• automatically if they clear browser cookies/history and return to the site with OneSignal code.
• re-enable push using the OneSignal Bell Prompt or Custom Link prompt

Mobile App Push Device Records will get automatically resubscribed when they open after they enabled push in the App Settings.

Email Resubscribe

If a user unsubscribes from email, they will get resubscribed if you manually click "Resubscribe to email" in the All Users tab for their record. Or if you call the setEmail method again for their record through the SDK.

SMS Resubscribe

If the device texted back "STOP" to the sending number, then they will not get SMS again until they text back "START" to the same number. You can set your own opt-out keywords in Twilio.

Once they opt-back-in, you can detect this with Twilio's Webhook for Incoming Messages and mark the device as subscribed in OneSignal using the Edit Device API with notification_types set to 1.

If you called the SDK logoutSMS method, you can resubscribe the SMS using the setSMSPhoneNumber method with the same phone number.

Player ID

The OneSignal Player ID is a UUID (Unique Universal Identifier) that OneSignal creates per device per OneSignal App ID.

The format is lowercase letters and numbers 8 characters-4 characters-4 characters-4 characters-12 characters like b3aaabc2-9a47-4647-adda-3e4583a2d19e.

A common practice is to tie the OneSignal Player ID with your User ID (we call External User Id). See our Internal Database, DMP, & CRM Integration Guide for more on this setup.

When does the OneSignal Player ID change?

Web Push - When the user clears their cookie data for your site.

Mobile Apps - If using version 3.4.1+ of our iOS SDK or 4.3.1+ of our Android SDK, the Player ID will always change when:

1. Deleting Users
2. Uninstalling and Re-installing the Mobile App or Installing the Mobile App on a new device

Earlier Versions of our Mobile SDKs, OneSignal makes a best effort to keep the same Player ID on all devices that are assigned. Some circumstances that may cause it to change:

• Android: If the user has opted out of the Google Advertising ID, uninstalls the app and re-installs.
• iOS: If the user does not have any other apps installed that have your IFV (identifierForVendor), then uninstalling your app and re-installing it, will give them a new Player ID.

Finding Player IDs

Please see Finding Users

External User IDs

The external_user_id is an identifier you set which helps map your unique database User ID's to the OneSignal player_id device record. This could be any unique identifier like Firebase User ID, CRM User ID, or even email if you choose.

To clarify:

• OneSignal creates the player_id for every device record
• You send OneSignal the external_user_id based on how you identify users.

Multiple device records in OneSignal can have the same external_user_id but will each have a unique player_id. For example, a user subscribed to your website, android mobile app and iOS mobile app will have 3 different player_id records, but you can map these devices to your database via the same external_user_id.

Our SDKs support a setExternalUserId method which you can call as soon as the user logs into your website and/or mobile apps to set their User Id.

More details in our Internal Database, DMP, & CRM.

FAQ

Managing Multiple Users On One Device

To manage multiple users that share a device, you will need to detect when User A is on the device and only send them their notifications when they are on the device, otherwise User B will get them.

The best way to handle this is with your own External User IDs.

Call the setExternalUserId method when each user signs in to the app, then you can target them by the external_user_id using the API include_external_user_ids parameter.

Once they log out of the app, you can remove the external_user_id with removeExternalUserId method. If using Identity Verification then removeExternalUserId does not work. Instead you can call setExternalUserId with an empty string for the External User Id and use the same User Auth Hash for the original external user id you are trying to remove.

This means if User A logs in and you call setExternalUserId("user_a") then any messages sent directly to user_b with include_external_user_ids will not be shown on the device until User A logs out, removeExternalUserId is called and User B logs in.

Managing One User On Multiple Devices

Use a custom User Id and set it with the setExternalUserId method whenever the user logs into the app.

Can I track users that have uninstalled my app?

Yes and no. Mobile operating system providers make it intentionally difficult to reliably detect when a user has uninstalled an app.

OneSignal does not differentiate an Uninstall vs Unsubscribe And Never Opening the App Again.

OneSignal detects the last time a device opened the app with the "Last Session" parameter. You can Export User Data to check the Subscription Status and Last Active time.