Curious about DNS and Tor

I got in a debate with someone the other day about TOR not needing DNS to function and they insisted that it did. That if the entire DNS system were to be shut down, TOR would go with it. Can anyone confirm if this is true or not?

I’m specifically talking about connecting to the TOR network and accessing TOR specific sites. I know things out on the DNS side would be down. My question is specifically about whether you’d still be able to access hidden TOR sites.



Tor should be able work without DNS. Relays communicate with each others based on their IP addresses, not domain names. Connections to onion services do not require DNS. Connection to clearnet services still require DNS (unless you know the IP beforehand).

That said, some things would break. For instance the Snowflake pluggable transport needs to do a DNS query before it can connect to Tor, so it wouldn’t work if DNS was down. But Snowflake isn’t really part of the Tor network, it’s “just” a way to get to Tor from network which tries to censor it.


Thanks for the response. I thought that to be the case but haven’t really seen a technical explanation of exactly how a tor client establishes a connection to the network and therefore wasn’t 100%. Still not totally. :slight_smile:

Yes. Onion addresses do not rely on or use DNS.

Here are some of the (deep) technicalities you desire. Note how this forum app uses DNS to try to lookup the .onion “domain” to generate a preview but can’t. The good news is Tor Browser & other browsers tuned into the tor network will show you the pages.


Go here for more technical explanations:

Or using DNS;