Welcome to the OnionShare wiki.
Securely and anonymously share files of any size. A web server is started, making OnionShare accessible as a Tor Onion Service, potentially temporarily or in a stealthy manner, over the Internet. An unguessable address is generated and is shared for the recipient to open in the Tor Browser to download the files. No separate server or third party file-sharing service required. You host the files on your own computer.
Open OnionShare, drag and drop files and folders into it, and click "Start Sharing". A secret .onion URL such as
http://asxmi4q6i7pajg2b.onion/egg-cain will be presented for you to share.
Send this URL to the recipient of the files. E-mail, or a Facebook or Twitter private message is fine if the content isn't secret. The files are no more secure than the means of sending the address.
The recipient doesn't need OnionShare. Opening the address in Tor Browser is all that is needed to download the file.