diff --git a/keyserver/src/push/send.js b/keyserver/src/push/send.js
--- a/keyserver/src/push/send.js
+++ b/keyserver/src/push/send.js
@@ -45,6 +45,7 @@
   fcmPush,
   getUnreadCounts,
   apnMaxNotificationPayloadByteSize,
+  fcmMaxNotificationPayloadByteSize,
 } from './utils';
 
 type Device = {
@@ -530,33 +531,41 @@
     allMessageInfos,
     threadInfo,
   );
-  const messageInfos = JSON.stringify(newRawMessageInfos);
-
-  if (badgeOnly && codeVersion < 69) {
-    // Older Android clients don't look at badgeOnly, so if we sent them the
-    // full payload they would treat it as a normal notif. Instead we will
-    // send them this payload that is missing an ID, which will prevent the
-    // system notif from being generated, but still allow for in-app notifs
-    // and badge updating.
-    return {
-      data: {
-        badge: unreadCount.toString(),
-        ...rest,
-        threadID: threadInfo.id,
-        messageInfos,
-      },
-    };
-  }
-  return {
+  const notification = {
     data: {
       badge: unreadCount.toString(),
       ...rest,
-      id: notifID,
       threadID: threadInfo.id,
-      messageInfos,
-      badgeOnly: badgeOnly ? '1' : '0',
     },
   };
+
+  // The reason we only include `badgeOnly` for newer clients is because older
+  // clients don't know how to parse it. The reason we only include `id` for
+  // newer clients is that if the older clients see that field, they assume
+  // the notif has a full payload, and then crash when trying to parse it.
+  // By skipping `id` we allow old clients to still handle in-app notifs and
+  // badge updating.
+  if (!badgeOnly || codeVersion >= 69) {
+    notification.data = {
+      ...notification.data,
+      id: notifID,
+      badgeOnly: badgeOnly ? '1' : '0',
+    };
+  }
+
+  const messageInfos = JSON.stringify(newRawMessageInfos);
+  const copyWithMessageInfos = {
+    ...notification,
+    data: { ...notification.data, messageInfos },
+  };
+
+  if (
+    Buffer.byteLength(JSON.stringify(copyWithMessageInfos)) <=
+    fcmMaxNotificationPayloadByteSize
+  ) {
+    return copyWithMessageInfos;
+  }
+  return notification;
 }
 
 type NotificationInfo =