OnionShare lets you securely and anonymously share files of any size. It works by starting a web server, making it accessible as a Tor hidden service, and generating an unguessable URL to access and download the files. It doesn't require setting up a server on the internet somewhere or using a third party filesharing service. You host the file on your own computer and use a Tor hidden service to make it temporarily accessible over the internet. The other user just needs to use Tor Browser to download the file from you.
You can set up your development environment to build OnionShare yourself by following [these instructions](/BUILD.md). You can also install OnionShare in your Tails persistent volume by following [these instructions](/tails/README.md).
Before you can share files, you need to open [Tor Browser](https://www.torproject.org/) in the background. This will provide the Tor service that OnionShare uses to start the hidden service.
Open OnionShare and drag and drop files and folders you wish to share, and start the server. It will show you a long, random-looking URL such as `http://cfxipsrhcujgebmu.onion/7aoo4nnzj3qurkafvzn7kket7u` and copy it to your clipboard. This is the secret URL that can be used to download the file you're sharing. If you'd like multiple people to be able to download this file, uncheck the "close automatically" checkbox.
Send this URL to the person you're trying to send the files to. If the files you're sending aren't secret, you can use normal means of sending the URL: emailing it, posting it to Facebook or Twitter, etc. If you're trying to send secret files then it's important to send this URL securely. I recommend you use [Off-the-Record encrypted chat](https://pressfreedomfoundation.org/encryption-works#otr) to send the URL.
The person who is receiving the files doesn't need OnionShare. All they need is to open the URL you send them in Tor Browser to be able to download the file.
