JavaScript PushManager registrations() Method

What You’ll Learn

PushManager.registrations() is a deprecated, non-standard instance method that listed existing push endpoint registrations as an array of PushRegistration objects. Learn what it did, why MDN replaced it with getSubscription(), how to feature-detect it, and modern migration patterns—with five examples and try-it labs.

Introduction

Before reusing or creating push endpoints, legacy Mozilla code needed to know what was already registered. Early push drafts exposed registrations() on PushManager to list existing endpoints with their version numbers.

MDN now marks it deprecated and non-standard. The standardized replacement is getSubscription(), which returns a single PushSubscription (or null) for the current service worker registration. Modern PWAs should never call registrations() in new code.

Understanding registrations()

A legacy instance method on PushManager that queried existing push endpoint registrations.

• Parameters — none.
• Returns — DOMRequest (not a Promise).
• Success result — array of PushRegistration objects.
• pushEndpoint — endpoint URL string on each object.
• version — current version of the push endpoint.
• Superseded by — getSubscription() (Baseline Widely available).
• Available in Web Workers per MDN (where still supported).

📝 Syntax

pushManager.registrations()

Return value

A DOMRequest object. On success, req.result is an array of PushRegistration objects with pushEndpoint and version.

MDN legacy pattern

// Legacy — do not use in new code (MDN sample used navigator.push)
const req = navigator.push.registrations();

req.onsuccess = () => {
  req.result.forEach((registration) => {
    console.log(
      `Existing registration ${registration.pushEndpoint} ${registration.version}`
    );
  });
};

⚖️ registrations() vs Modern APIs

Examples Gallery

Examples explain legacy registrations() and show modern getSubscription() replacements. Use View Output or Try It Yourself.

const req = navigator.push.registrations();

req.onsuccess = () => {
  if (req.result.length > 0) {
    req.result.forEach((registration) => {
      console.log(
        `Existing registration ${registration.pushEndpoint} ${registration.version}`
      );
    });
  } else {
    console.log("No existing registrations");
  }
};

Existing registration https://push.example.com/… 1

function legacyRegistrations(pushManager) {
  if (typeof pushManager.registrations === "function") {
    return pushManager.registrations();
  }
  if (navigator.push && typeof navigator.push.registrations === "function") {
    return navigator.push.registrations();
  }
  return null; // not supported — use getSubscription()
}

null — registrations not supported, use getSubscription()

const req = navigator.push.registrations();

req.onsuccess = () => {
  if (req.result.length > 0) {
    // Reuse existing endpoints
    req.result.forEach((r) => sendEndpointToServer(r.pushEndpoint));
  } else {
    // Legacy: register for a new endpoint
    const registerReq = navigator.push.register();
    registerReq.onsuccess = () => {
      console.log(`Registered new endpoint: ${registerReq.result}`);
    };
  }
};

Registered new endpoint: https://push.example.com/…

const registration = await navigator.serviceWorker.ready;

const subscription = await registration.pushManager.getSubscription();

if (subscription) {
  console.log("Existing:", subscription.endpoint);
  await syncSubscriptionToServer(subscription);
} else {
  console.log("Not subscribed — show enable UI");
}

Not subscribed — show enable UI

async function updatePushButton() {
  const registration = await navigator.serviceWorker.ready;
  const subscription = await registration.pushManager.getSubscription();
  const btn = document.querySelector(".js-push-button");

  if (subscription) {
    btn.textContent = "Push Enabled";
    btn.dataset.endpoint = subscription.endpoint;
  } else {
    btn.textContent = "Enable Push";
  }
}

updatePushButton();

Enable Push

🚀 Common Use Cases (Historical)

• Reading old Mozilla push tutorials that call registrations().
• Maintaining legacy Firefox OS apps with navigator.push.
• Understanding why getSubscription() returns one object, not an array.
• Migrating endpoint-list code to PushSubscription objects.
• Pairing with deprecated register() in legacy flows.

🔧 How It Works

📝 Notes

• Deprecated & non-standard on MDN—not for new production code.
• Superseded by getSubscription() (Baseline Widely available).
• Not Experimental — it was Mozilla-specific and removed from specs.
• DOMRequest — callback-based; unlike modern Promise APIs.
• Multiple endpoints — legacy could return an array; modern API returns one subscription per SW.
• Related learning: getSubscription(), register(), permissionState(), JavaScript hub.

💡 Best Practices