SendX allows you to preview your WebPush broadcast messages in real time. Using this feature, you can view your WebPush message exactly as it will appear and make adjustments as needed.
Create a new WebPush broadcast campaign or edit an existing one to preview it.
After you're done creating the message, scroll down and click the Preview button at the bottom.

That’s it! You will now be able to see your WebPush message on the top right, exactly as it will be broadcast to your list of contacts.