Cloudflare does not automatically block visitors who use the Tor network. You can control Tor access via the Firewall app and enable Onion Routing in the Crypto app.
Why might a Tor visitor be blocked or challenged?
Due to the behavior of some individuals using the Tor network (spammers, distributors of malware, attackers, etc.), the IP addresses of Tor exit nodes may earn a bad reputation, elevating their Cloudflare threat score.
Our basic protection level issues CAPTCHA-based challenges to visitors whose IP address has a high threat score, depending on the level chosen by the Cloudflare customer. The choices for security range from Essentially Off to I'm Under Attack. The default level is Medium.
What additional control do Cloudflare customers have over traffic from visitors using Tor?
Since February 2016, Cloudflare treats Tor exit nodes as a "country" of their own. There's no geography associated with these IPs, but this approach lets Cloudflare customers override the default Cloudflare threat score to define the experience for their Tor visitors.
Cloudflare updates its list of Tor exit node IP addresses every 15 minutes.
Control is in the IP Firewall > Access Rules panel of the Cloudflare dashboard Firewall app. Learn more about Access Rules.
The options for Tor are:
- Block - blacklist
- Challenge - visible CAPTCHA challenge, the visitor must interact with it to pass
- Whitelist - trust
Cloudflare uses the two-letter code T1 for Tor.
Here's an example where a Cloudflare customer chooses in their dashboard to Whitelist Tor.
What does a Tor visitor see when CAPTCHA is selected?
A Tor visitor to any Cloudflare site which has chosen to CAPTCHA (challenge) Tor will see a page like this and need to proceed through the CAPTCHA, which may have different actions required.
What does a Tor visitor see when Blocked selected?
Tor visitors to a Cloudflare site which has chosen to Block Tor will see Error 1009, as shown below:
Does Cloudflare support Onion Routing?
Beyond applying firewall filters to Tor traffic, Cloudflare users can improve the Tor user experience by enabling Onion Routing.
Onion Routing allows Cloudflare to serve your website’s content directly through the Tor network, without requiring exit nodes required. This improves Tor browsing as follows:
- Tor users no longer will access your site via exit nodes, which can sometimes be compromised, and may snoop on user traffic.
- Human Tor users and bots can be distinguished by our Onion services, such that CAPTCHA challenges are only served to malicious bot traffic.
You can toggle this setting on or off in the Onion Routing panel of the Cloudflare dashboard Crypto app.