If you cannot reach the onion service you desire, make sure that you have entered the 56-character onion address correctly; even a small mistake will stop Tor Browser from being able to reach the site. If you are still unable to connect to the onion service, please try again later. There may be a temporary connection issue, or the site operators may have allowed it to go offline without warning.

You can also ensure that you're able to access other onion services by connecting to DuckDuckGo's onion service.

How do I know if I'm using v2 or v3 onion services?

You can identify v3 onion addresses by their 56 character length, e.g. Tor Project's v2 address:https://expyuzz4wqqyqhjn.onion/, and Tor Project's v3 address: https://2gzyxa5ihm7nsggfxnu52rck2vv4rvmdlkiu3zzui5du4xyclen53wid.onion/

If you're an onion service administrator, you must upgrade to v3 onion services as soon as possible. If you're a user, please ensure that you update your bookmarks to the website's v3 onion addresses.

What is the timeline for the v2 deprecation?

In September 2020, Tor started warning onion service operators and clients that v2 will be deprecated and obsolete in version 0.4.6. Tor Browser started warning users in June, 2021.

In July 2021, 0.4.6 Tor will no longer support v2 and support will be removed from the code base.

In October 2021, we will release new Tor client stable versions for all supported series that will disable v2.

You can read more in the Tor Project's blog post Onion Service version 2 deprecation timeline.

Can I keep using my v2 onion address? Can I access my v2 onion after September? Is this a backward-incompatible change?

V2 onion addresses are fundamentally insecure. If you have a v2 onion, we recommend you migrate now. This is a backward incompatible change: v2 onion services will not be reachable after September 2021.

What is the recommendation for developers to migrate? Any tips on how to spread the new v3 addresses to people?

In torrc, to create a version 3 address, you simply need to create a new service just as you did your v2 service, with these two lines:

HiddenServiceDir /full/path/to/your/new/v3/directory/
HiddenServicePort <virtual port> <target-address>:<target-port>

The default version is now set to 3 so you don't need to explicitly set it. Restart tor, and look on your directory for the new address. If you wish to keep running your version 2 service until it is deprecated to provide a transition path to your users, add this line to the configuration block of your version 2 service:

HiddenServiceVersion 2

This will allow you to identify in your configuration file which one is which version.

If you have Onion-Location configured on your website, you need to set the header with your new v3 address. For technical documentation about running onion services, please read the Onion Services page in our Community portal.

I didn't see the announcement, can I get more time to migrate?

No, v2 onion connections will start failing nowish, first slowly, then suddenly. It's time to move away.

Will services start failing to be reached in September, or before already?

Already, introduction points are not in Tor 0.4.6 anymore, so they will not be reachable if relay operators update.

As a website administrator, can I redirect users from my v2 onion to v3?

Yes, it will work until the v2 onion address is unreachable. You may want to encourage users to update their bookmarks.

Are v3 onion services going to help in mitigating DDoS problems?

Yes, we are continuously working on improving onion services security. Some of the work we have in our roadmap is ESTABLISH_INTRO Cell DoS Defense Extension, Res tokens: Anonymous Credentials for Onion Service DoS Resilience, and A First Take at PoW Over Introduction Circuits. For an overview about these proposals, read the detailed blog post How to stop the onion denial (of service).

When browsing an Onion Service, Tor Browser displays different onion icons in the address bar indicating the security of the current webpage.

An onion means:

• The Onion Service is served over HTTP, or HTTPS with a CA-Issued certificate.
• The Onion Service is served over HTTPS with a Self-Signed certificate.

An onion with a red slash means:

• The Onion Service is served with a script from an insecure URL.

An onion with caution sign means:

• The Onion Service is served over HTTPS with an expired Certificate.
• The Onion Service is served over HTTPS with a wrong Domain.
• The Onion Service is served with a mixed form over an insecure URL.

Onion-Location is a HTTP header that web sites can use to advertise their onion counterpart. If the web site that you're visiting has an onion site available, a purple suggestion pill will prompt at the URL bar saying ".onion available". When you click on ".onion available", the web site will be reloaded and redirected to its onion counterpart. At the moment, Onion-Location is available for Tor Browser desktop (Windows, macOS and GNU/Linux). You can learn more about Onion-Location in the Tor Browser Manual. If you're an onion service operator, learn how to configure Onion-Location in your onion site.

Onion services allow people to browse but also to publish anonymously, including publishing anonymous websites.

Onion services are also relied on for metadata-free chat and file sharing, safer interaction between journalists and their sources like with SecureDrop or OnionShare, safer software updates, and more secure ways to reach popular websites like Facebook.

These services use the special-use top level domain (TLD) .onion (instead of .com, .net, .org, etc.) and are only accessible through the Tor network.

When accessing a website that uses an onion service, Tor Browser will show at the URL bar an icon of an onion displaying the state of your connection: secure and using an onion service.

To learn more about onion services, read How do Onion Services work?

An authenticated onion service is an onion service that requires you to provide an authentication token (in this case, a private key) before accessing the service. The private key is not transmitted to the service, and it's only used to decrypt its descriptor locally. You can get the access credentials from the onion service operator. Reach out to the operator and request access. Learn more about how to use onion authentication in Tor Browser. If you want to create an onion service with client authentication, please see the Client Authorization section in the Community portal.

Websites that are only accessible over Tor are called "onions" and end in the TLD .onion. For example, the DuckDuckGo onion is https://duckduckgogg42xjoc72x3sjasowoarfbgcmvfimaftt6twagswzczad.onion/. You can access these websites by using Tor Browser. The addresses must be shared with you by the website host, as onions are not indexed in search engines in the typical way that vanilla websites are.

Yes! A list of our Onion Services is available at onion.torproject.org.