People who tweet urls:your tweet is going to get shorter.
Any tweet that includes a url will now be reduced by 2 characters from today. This takes it to 118 characters, or 117 for https links. This was first announced to the Twitter development community by Twitter in December. It’s just now being implemented and goes live today.
Such change is a result of Twitter’s t.co link wrapper. Since it extends the maximum length of a link wrapped by t.co from 20 to 22 characters for non-https URLs, and from 21 to 23 characters for https lengths, you now have less tweet landscape to work with.
When Twitter users post a link within a tweet, Twitter automatically wraps the link in their own proprietary wrapper (t.co). This happens even if another url shortener is used such as bit.ly and others. Twitter supports this method as they believe it helps keep the Twitter ecosystem safe and helps avoid computer viruses. There are obviously key benefits to them being able to track all urls for watching trends and enabling future monetization on such data in the future.