OnionRouter by LouisCourrian

OnionRouter lets you visit .onion websites in your regular Firefox without installing the Tor Browser or configuring anything manually.

What it does

When you type a .onion URL, OnionRouter automatically routes the request through a local Tor proxy. Non-.onion traffic stays direct unless you explicitly enable one of the other routing modes.

Three routing modes

• Onion only (default): only .onion URLs go through Tor.
• All via Tor: every Firefox request goes through Tor (WebRTC is auto-disabled).
• Whitelist: .onion URLs plus a user-controlled list of domains go through Tor.

Privacy details

• DNS-via-Tor (proxyDNS) prevents your DNS resolver from seeing the .onion or whitelisted hostnames you visit.
• WebRTC kill-switch automatically disables peer-connections in "All via Tor" mode and is user-toggleable in other modes.
• The Rust companion uses the official Tor Expert Bundle directly from dist.torproject.org, with SHA-256 verification against pinned hashes.
• If you already have Tor Browser or system Tor running, OnionRouter verifies it via the Tor Control Port (PROTOCOLINFO + AUTHENTICATE + GETINFO version) and reuses it rather than starting a duplicate.

How it's built

OnionRouter is split into two parts:

• This Firefox extension (Manifest V3) — handles UI, request routing and Firefox-level privacy settings.
• A small Rust companion program (~1 MB, open source) installed via a separate Windows installer. The companion speaks Mozilla's Native Messaging protocol and is what actually downloads, verifies and runs the Tor binary.

The companion source code, the verification hashes, and the build pipeline are all auditable at github.com/LouisCourrian/OnionRooter.

Requirements

• Firefox 115 or newer
• Windows 10/11 (Linux and macOS installers planned)
• About 50 MB of disk space for the cached Tor binary on first run