Web Push Notifications are a fast and easy way to reach out to your subscribers in real-time. However, it is not uncommon to observe that some users do not receive the sent push notifications. It is Normal!
We have compiled bellow a list with some of the reasons explaining why the delivery rate cannot be at a 100% rate.
1- Failure in Connecting to GCM:
If your subscribers haven’t been connected to the internet for a while, GCM may fail to deliver notifications to their device. Long haul internet connectivity is another contributing factor.
2- GCM is unable from marking such users as inactive.
In order to maintain a user’s connection status as “Active” android devices send heartbeats at an interval of 30 minutes for cellphone networks and 15 minutes for Wi-Fi connections.
As per Google, around 15% of users fail to connect to GCM due to internet connectivity issue. Hence, such users do not receive web push notifications.
Firewall settings may block the sent notifications. This could be the case in corporate environments where security measures are tightened. Your subscriber might need to request the assistance of his security team to enable receiving push notifications.
4- Web Push Notification expiry:
If your website subscriber has been disconnected from the internet for a long period of time, has disabled his mobile device background activity or uninstalled the browser app, the chances are that this user won’t be receiving the push notification you have sent him since Web Push Notifications have an expiration time frame.
5- Uninstallation of Browser app:
If a user uninstalls his browser app and a push notification has been sent to this user, GCM will attempt to send the notification to the device couple of times before marking the device as non-functional
6- Battery saver mode Activated:
If users change their battery settings to Saver mode to stop Battery from draining power quickly. This forces some apps to stop from running on the device hence your users won’t receive any notifications.
7- Technical issues on some devices:
Some mobile device makers do not allow web push notifications when apps are not running neither in the background nor in the front. These Mobile Makers such as Xiaomi are working on solving this issue on their new releases.
8- Subscriber clears other site data:
When users clear other site data from Chrome, the service workers are uninstalled denying your website from sending any notifications to this user.
Service Worker*: Act as proxy servers that sit between web applications, the browser, and the network, intended, among other things, to enable the creation of effective offline experiences, intercept network requests and take appropriate action based on whether the network is available, and update assets residing on the server.