After testing two about months, in the limit of 280 characters, the Twitter starting today to feature the new limit for everyone.
Twitter says you shouldn't now expect to see massive tweets of 280 characters right away.
According to the data collected by company, the number of tweets with higher than average characters was very small. In fact, only 5% of tweets sent by those testing the new feature exceeded the 140 character limit.
According to Twitter's product manager Aliza rosen:
"Είδαμε ότι χρειάζονταν περισσότεροι από 140 χαρακτήρες, αλλά υπήρχαν πάρα πολλά tweets με κάτω από 140 χαρακτήρες"
The new character limit will be available in all languages that have problems with the older limit.
According to a spokesman, Japanese, Korean and Chinese do not require a higher limit because of the characters they use as each character may have a different meaning.
