Here's how to switch to 280 characters in Twitter on your own, before extending the function promised by Twitter to everyone.
Twitter has recently announced its intention to expand the space available for tweets from 140 to 280 characters, thus double the amount of expressive space previously available. The functionality for, at the moment, in the testing phase with a limited number of randomly selected users and this has led some intrepid Twitter users to look for ways to circumvent the obstacle and can now use double space for tweets. We've gathered here some of the possible ways to switch to 280 characters independently, before extending the promised function to everyone.
>>> Now official Twitter for 280 for all: Read HERE the update <<<
Tweet 280: the 280 characters immediately
The char280 extension
The staff of The Next Web has identified ways to make changes to the Tweetdeck Developer menu in order to allow 280 characters and because this functions obviously need to use Tweetdeck.
Use a TamperMonkey script
The user of Twitter @ Prof9 has discovered that it is possible to use the Chrome TamperMonkey extension to install a userscript that enables tweeting to 280 characters.
Here is the extension for Chrome: https://chrome.google.com/webstore/detail/tampermonkey/dhdgffkkebhmkfjojejmpbldmpobfkfo?hl=en
Here is the script: https: //gist.github.com/Prof9/c16fc4997e0ef5b22a15c43edd7f5f49