Epic giffage on is now possible on Twitter. The microblogging platform has quietly increased the maximum size for gifs from 5MB to 15MB. There has been no official announcement, but the updated Twitter help page now reads, "Photos can be up to 5MB; animated GIFs can be up to 5MB on mobile, and up to 15MB on web."
As noted, images are still restricted to 5MB, and gif size is still restricted to 5MB when using Twitter's mobile apps. Twitter has recently also increased the length of Vine videos from 30 seconds to 130 seconds, and is rolling out an update where @names and media attachments will no longer count towards the 140 character Tweet limit.