Maria,
This site gives a complete breakdown of all the push limits per OS and browser along with mobile limits - https://getfirepush.com/blog/what-is-the-best-length-for-push-notifications/
According to that site - The ideal character limit for push notifications is around 39 characters for the title and 150 characters for the message. This limit ensures a full display of push notification and applies to most devices, browsers, and operating systems.
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