Onionshare is described as 'Web servers are started locally on your computer and made accessible to other people as Tor onion services' and is a popular app in the file sharing category. There are more than 25 alternatives to Onionshare for a variety of platforms, including Windows, Linux, Mac, Online / Web-based and Android. The best alternative is Syncthing, which is both free and Open Source. Other great apps like Onionshare are RetroShare, Send Anywhere, Wormhole.app and Send.
RetroShare is a open source cross-platform, private and secure decentralized communication system. It lets you to securely chat, share photos, videos, and more, using OpenPGP to authenticate peers and .
RetroShare vs Onionshare opinions
pros, cons and recent comments
Retroshare is a full swiss army knife of many secure, anonymous decentralized communication tools including file sharing. Optionally easily proxied via Tor,I2P and Optionally fully routed via Tor, I2P as a Hidden Service also.
Simple, private file sharing
Wormhole lets you share files up to 10GB with end-to-end encryption and a link that automatically expires. So you can keep what you share private and make sure your stuff doesn't stay online forever.
Bitwarden Send is a lightweight utility used to share information with another person for a limited period of time. Bitwarden users can easily transmit a file or text, and rest easy knowing the sent information is protected with end-to-end encryption, and will not live forever.