Push Notifications Guide

An overview of the App Push Notifications and customizations available.

Push Notifications are "Rich Text" Format messages that get pushed from the FCM and APNS servers to your subscribers. Devices subscribe or "opt-in" to receive push notifications usually through a prompt on iOS apps. Android App Subscriptions happen as soon as the device downloads and opens the app for the first time.


Web Push Notifications Guide

For website push, see our Web Push Notifications Guide.

Here are common layout guides to follow for push notifications across all platforms:

Notification ContentDetails
Character LimitsHow many characters are allowed and recommended per platform?
Emoji support is available across all platforms :thumbsup:
ImagesLarge Banner Images that appear with the notification. Supported by Android, iOS, and Web.
IconsSupported on all platforms.
Notification SoundsSupported for Android and iOS mobile apps. Not customizable on Web Push.
BadgesRed dots with numbers for Android and iOS mobile apps. Web Push Badges are the small icons on Chrome for Android.
Call to Action ButtonsCustom buttons that can support different actions or links.

You can also control some aspects of the Notification's Behaviour & Payload such as how long the push will be held by the FCM/APNS when the device is offline, collapsing notifications, etc.

Notification BehaviourDetails
Deep-links and URLs
(Additional Data)
When notification is clicked, send users to a custom URL or an activity within the app.
Time To LiveHow long is the push saved on the FCM/APNS/VAPID servers if the user's device is offline/not reachable?
Show LatestOverrides the notifications already present on the user's device if the current notification contains the same override_tag.


Because each platform uses a different visual layout for messages, the amount of content that is visible varies. For websites, please see our Web Push Notifications Guide.

Character Limits

The following are approximations for the number of characters in a notification based on the respective platforms. Please refer to our Allowed Values guide for details around this.

Emojis count as a single character. You can simply copy & paste the emoji needed in the Title or the Message.

Android~ 25 to 50~ 150
iOS~ 50~ 150
Best fit for all platforms
(including web push)
~ 20~ 60


You can copy & paste emojis directly into the Title and Message fields of the notification. Or, you can use the emoji picker available on the Send Notification page on the panel.
Any standard emoji will work and you can use https://getemoji.com/ for more.


Emoji Limitations

Emojis are controlled by the operating system that is receiving the notification and must support the emoji for it to be seen.

App Name

The App Name shown on the push can be changed by the following settings. Websites cannot change the website URL shown on the push, it must always show the site origin the user is subscribed to.

AndroidChange the <application android:label="YOUR APP NAME"> in the AndroidManifest.xml file.
iOSChange Display Name set in XCode.


For large images for mobile apps, please refer to our Images and Rich Media guide. For websites, see our Web Push Notifications Guide.

Images can be added by using:

  1. The panel
  2. Rest API

Recommended Image Details

Filetypesjpg, jpeg, png, gifjpg, jpeg, png
ResolutionRecommendations: 2:1 aspect ratio landscape

Max Width: 2000 pixels
Min Width: 300 pixels

Common sizes:
Recommendations: 2:1 aspect ratio landscape

Max Width: 2000 pixels
Min Width: 300 pixels

Common sizes:
API Parameterbanner_urlbanner_url
  • gif image animations are not supported on Android mobile apps.
  • Adding Call to Action Buttons may affect image sizes. Please see the preview of the notification on the Send Notification page to make sure the layout fits your requirements.
  • Android 4.1+ and iOS 10+ support large images.
  • For troubleshooting, please refer to Notification Images Not Shown on Device guide.


All push notifications support some type of icon. For website push, please see our Web Push Notifications Guide.

Mobile Push Icons are set within your mobile app. Android Mobile App Large icons can use external resources. iOS only uses the main app icon.

Creating a CampaignAndroid Notification Icons guideUses the app's default icon
Rest API Icon Parametersicon_urlUses the app's default icon


iZooto supports adding custom sounds for any app push notification. To learn more, please refer to our guide on Notification Sounds.


Please refer to our Badges guide.

Call to Action Buttons

iZooto supports acton buttons on all platforms. Please see our Call to Action Buttons document for more details.

Notification Behaviour

Please refer to the Advanced Notifications Settings documentation to understand how to set up Show Latest (Notification Override), Time to Live, and other common setup features.

Notifications in an On-Premise Closed Network

A common question around push notifications is if iZooto can send notifications in an On-Premise Closed Network?

This can work as long as the computers/mobiles have access to the push gateway servers that you want to support:

If the network is completely disconnected from the Internet, push notifications cannot be delivered via the standard OS/browser services, which is what we support.