I see less text in non ASCII alphabets

Short answer : The Push notifications Apple allows us to send are limited in size, the non ASCII alphabets uses UTF8 or UTF16 and therefor you will have a shorter message (half the size or 4 times shorter depending of the alphabet).

Long answer : Apple requests to send push notifications in the JSON format. Non ASCII alphabets, when JSONified, are taking more spaces than ASCII alphabets. Example using a Ruby IRB console :

"واغلق".to_json

""\u0648\u0627\u063a\u0644\u0642""

"واغلق".to_json.length

32

"واغلق".length

10

If anyone has a solution I'd be glad to fix this.