LocalSend is described as 'Free open-source tool offers secure, end-to-end encrypted file and message sharing over local networks across major desktop and mobile operating systems' and is a very popular large file transfer service in the file sharing category. There are more than 100 alternatives to LocalSend for a variety of platforms, including Windows, Android, Mac, Web-based and Linux apps. The best LocalSend alternative is KDE Connect, which is both free and Open Source. Other great apps like LocalSend are PairDrop, OnionShare, Blip and RetroShare.