Declarative Web Push subscription scope on iOS

Behaviour · Measured 2026-10-20, iPhone 16 Pro, iOS 18.6.2 (22G100) · A, Instrumented read · Adds a condition

From iOS 18.4 a page can subscribe to push through window.pushManager (Declarative Web Push) as well as through a service worker registration. On an iPhone 16 Pro running iOS 18.6.2 (22G100), window.pushManager existed in a Safari tab. In Home Screen apps it did not return the subpath-scoped worker’s subscription (2026-10-20).

On iOS, when a Home Screen web app’s service worker is scoped to a subpath and subscribes through its registration, does window.pushManager.getSubscription() return that subscription? Does one permission grant cover both managers? And is window.pushManager exposed in a plain Safari tab?

Two subscription managers

Two Home Screen apps were used, each with a worker scoped below the site root: the Device Lab harness “PWA Lab” (scope /lab/device-tests/) and the OpenPWA demo (scope /demo/). In each app the subscription was made through registration.pushManager.subscribe() with userVisibleOnly: true and an application server key. We recorded these values, keeping only the endpoint’s host:

• For registration.pushManager.getSubscription(), we recorded the endpoint host and path length. We also recorded expirationTime and options.userVisibleOnly and checked whether the applicationServerKey matched;
• window.pushManager.getSubscription();
• permissionState({userVisibleOnly: true}) on both managers before the grant and again afterward.

In a Safari tab we checked exposure only. We read 'pushManager' in window and the types of its subscribe and permissionState members, along with getSubscription. We also checked 'PushManager' in window and 'Notification' in window. window.pushManager.subscribe() was not called in any context, and no root-scoped worker was tested.

How to run

Steps 4 and 5 need Web Inspector. On the iPhone, turn Settings → Apps → Safari → Advanced → Web Inspector on. On a Mac, select Safari → Develop → the iPhone → the app’s page.

1. In Safari on the iPhone, open https://openpwa.net/lab/device-tests/ and read the Results panel (T5, T9, T10). It prints 'pushManager' in window and the types of window.pushManager.subscribe and permissionState. It also prints 'PushManager' in window and 'Notification' in window.
2. Add the page to the Home Screen (Share, Add to Home Screen, Add) and launch PWA Lab.
3. Tap 1. Request permission, allow it, then tap Subscribe to push. The result line names the endpoint host.
4. In the Web Inspector console, evaluate (await navigator.serviceWorker.getRegistration()).pushManager.getSubscription() and await window.pushManager.getSubscription(). Record the endpoint host only, not the full endpoint or keys.
5. Evaluate await window.pushManager.permissionState({userVisibleOnly: true}) and the same call on the registration’s pushManager.

• T10 Declarative Web Push detection (2 min)
  Harness v1: Open the test
  Demo page: /demo/push/
• T7 Notification permission and push subscription (5 min)
  Harness v1: Open the test: PWA Lab, t7/perm
  Demo page: /demo/push/

Results

On iOS 18.6.2 (22G100), in the PWA Lab app the registration’s subscription had an endpoint on web.push.apple.com, a path length of 172, expirationTime null, userVisibleOnly true and the harness’s key, while window.pushManager.getSubscription() returned null (Instrumented read, A; notebook N33). The demo app also returned endpoint host web.push.apple.com with expirationTime null. Its window.pushManager.getSubscription() returned null too (A; N41). One permission grant set both managers’ permissionState to granted, in PWA Lab and in the freshly installed Perm Test app (A; N32, N54).

In a plain Safari tab 'pushManager' in window was true. Both subscribe and permissionState were functions, as was getSubscription, while 'PushManager' in window and 'Notification' in window were false (A; N03, N10). We did not try window.pushManager.subscribe() in a tab; these reads establish only that the object exists.

2026-10-20, iOS 18.6.2

One permission grant covered both push managers. With a worker scoped to a subpath (/lab/device-tests/, /demo/), the worker's web.push.apple.com subscription was not returned by window.pushManager.getSubscription() (null). window.pushManager also exists in a plain Safari tab, where PushManager and Notification do not; subscribe() was not tried in the tab. A root-scoped worker was not tested.

Date

2026-10-20

Device

iPhone 16 Pro

OS and build

iOS 18.6.2 (22G100), release

Context

Safari tab and Home Screen app

Result

As expected

Key values

• permissionGrantsShared: true
• workerSubscriptionHost: web.push.apple.com
• windowGetSubscription: null
• workerScopes: /lab/device-tests/, /demo/
• tabWindowPushManager: true
• tabPushManagerInterface: false
• tabNotification: false
• rootScopedWorker: not tested

Confidence

A, Instrumented read

Tests

T10, T7

Notebook entries

N03, N32, N33, N41

Study

Read the study · Data package

Harness

Harness v1

Harness v1 files used (3), served SHA-256

• /lab/device-tests/ 42c90845419f5ed3ad15d941bea04f649f4c5d350b1847292292fadd55871486
• /lab/device-tests/manifest.webmanifest cab4e60719fd1f9c84d04aada2ad6cd937f50615ce646c3ed20f14f0ca09832b
• /lab/device-tests/sw.js 0e7e6f34cb814d808edba644d664bac0f4337cc59a88dbb509d25a8e11fffc30

Root scope and Home Screen requirements

WebKit’s Meet Declarative Web Push post (webkit.org) says that a registered service worker “scoped to the root level of your website domain” shares the window’s push subscription. The subpath result agrees with that rule for the case it leaves out: with a worker below the root, the window manager did not return the worker’s subscription. The rule’s positive case, a root-scoped worker, was not tested here, so this run neither confirms nor contradicts it. The shared permission is not stated in the post.

WebKit’s Safari 18.4 post makes Declarative Web Push available “on iOS and iPadOS 18.4 for web apps added to the Home Screen” (WebKit Features in Safari 18.4, webkit.org), and BCD records api.Window.pushManager from Safari for iOS 18.4, marked experimental (Window.json, github.com). Neither says whether the object exists in an ordinary tab. The tab result therefore adds a condition. On 18.6.2 the object is exposed in a tab that has no Notification and no PushManager, so 'pushManager' in window does not show that push can be used there. The Push API defines window.pushManager through a PushManagerAttribute mixin that Window includes in secure contexts (Push API, w3.org); it does not describe the Home Screen condition that WebKit’s post states.

As far as the study’s prior-art check found, the tab exposure had not been published before. The subpath subscription result is consistent with WebKit’s description and adds a measured case.

Data

The values are in the study’s data package (CC BY 4.0): the tab side in raw/2026-10-20-ios18.6.2-tab-lab.json (N03) and raw/2026-10-20-ios18.6.2-step03-tab-demo-push.json (N10); PWA Lab in raw/2026-10-20-ios18.6.2-step19-app-lab-perm.json (N32) and raw/2026-10-20-ios18.6.2-step20-app-lab-sub.json (N33); the demo in raw/2026-10-20-ios18.6.2-step25b-app-demo-push.json (N41); Perm Test in raw/2026-10-20-ios18.6.2-25c-post-app-perm.json (N54). No raw file holds a full endpoint. The machine-readable run is in /lab/results.json under the id declarative-web-push-subscription-scope/2026-10-20-ios-18.6.2-22g100.

Related reference entries

The result backs the Declarative Web Push paragraphs of Web Push on iOS and iPadOS and Web Push and PushManager.subscribe(), and the condition on the Declarative Web Push row of the Web Push compatibility data.

Reference entries

• Web Push and PushManager.subscribe()
• Web Push on iOS and iPadOS (16.4+)

Compatibility data

• Web Push, row Safari (iOS) · Declarative Web Push

Limits

• One device, one build, one operator, one run day: an iPhone 16 Pro on iOS 18.6.2 (22G100).
• Both workers were scoped to a subpath. A root-scoped worker, the case WebKit’s rule covers, was not tested.
• window.pushManager.subscribe() was not called, in either a tab or an app. The run therefore does not establish whether a window subscription is visible to the worker or whether a tab can subscribe.
• No push message was delivered; the harness has no push server.
• The demo app’s prompt rests on the operator’s report; its permission state and subscription are instrumented reads.
• iPadOS and macOS Safari were not tested, nor were other iOS builds. The same device is due to be rerun after its upgrade to iOS 27.

Device steps performed by an OpenPWA operator on an iPhone 16 Pro. AI agent sessions read page state over USB, kept the notebook and drafted this text; automated gates and an AI fact-check checked it. No person reviews each entry.