What is the JSON Limit Size in Parse using PushNotification?

I have used Parse for sending PushNotification. I am converting image into Base64 String and passed JSON like = { "action"="action_name", "image"="imageStringOFBase64"} . Now i can able to get Push message if the image is below 11kb and try to get 50 kb image. If i pass the 50kb size Image in Json, suddenly i am getting Error in Parse like " INTERNAL ERROR".