Character Limits
The length of notification title and message depends on a number of factors including screen size, width, and input language. It may vary from device to device. The total permissible data limit is 4 KB. If the number of characters exceeds the limit suited for a device type, the title/message may appear trimmed (followed by …) when delivered on that device.Example
Here’s an example of how a trimmed title/message may appear on Mac.