Twitter Loosens Tweet's LeashTwitter on Tuesday announced a number of changes to tweets, including what will be included in a message's 140-character count. The changes will be rolled out in the coming months. When replying to a tweet, tagged @names at the beginning of the reply no longer will be included in the character count. Photos, GIFs, videos, polls and quote tweets won't be counted against the character limit.
Source:
Twitter Loosens Tweet's Leash