OnionShare — Secure Anonymous File Sharing via Tor

Introduction

OnionShare is an open-source tool that lets you securely share files, receive files, host static websites, and run anonymous chat rooms using Tor onion services. It creates a temporary .onion address directly on your machine, so data never passes through a third-party server and both sender and receiver can remain anonymous.

What OnionShare Does

• Shares files by creating a temporary Tor onion service with a unique URL
• Receives files from others through an anonymous upload portal
• Hosts static websites as .onion hidden services
• Runs ephemeral chat rooms over Tor with no accounts or registration
• Operates without any centralized server or cloud dependency

Architecture Overview

OnionShare connects to the Tor network and creates an ephemeral onion service on the local machine. For file sharing, it runs a lightweight web server accessible only through the generated .onion address. Files are served directly from disk with no intermediate storage. The URL includes a private key slug for access control. When the transfer completes or the application closes, the onion service disappears, leaving no trace.

Self-Hosting & Configuration

• Install via package manager on Linux, Homebrew on macOS, or download for Windows
• No configuration required for basic usage; just select files and share
• Use the CLI version for headless servers and automated workflows
• Configure persistent onion addresses for long-running websites or receive portals
• Optionally set passwords for additional access control on shared links

Key Features

• End-to-end anonymous file transfer with no middleman servers
• Built-in Tor integration requiring no separate Tor Browser for the sender
• Desktop GUI and command-line interface for flexible usage
• Auto-stop sharing after files are downloaded once for security
• Cross-platform support for Windows, macOS, and Linux

Comparison with Similar Tools

• Magic Wormhole — uses relay servers; OnionShare routes entirely through Tor
• croc — requires a relay; OnionShare is fully peer-to-peer via Tor
• Firefox Send (discontinued) — centralized server; OnionShare is decentralized
• SecureDrop — designed for whistleblower submissions; OnionShare is for general secure sharing
• Syncthing — continuous sync tool; OnionShare is for one-time secure transfers

FAQ

Q: Does the recipient need Tor Browser to download files? A: Yes. The .onion URL is only accessible through the Tor network, typically via Tor Browser.

Q: How fast are transfers over Tor? A: Speeds are limited by the Tor network, typically 1-5 MB/s. It prioritizes privacy over throughput.

Q: Can I share files with multiple people simultaneously? A: Yes. Multiple recipients can access the same .onion URL. You can disable auto-stop to keep sharing active.

Q: Is OnionShare audited? A: Yes. OnionShare has undergone independent security audits and is recommended by journalists and privacy organizations.

Sources

• https://github.com/onionshare/onionshare
• https://onionshare.org/