When browsing an Onion Service, Tor Browser displays different onion icons in the address bar indicating the security of the current webpage.
A green onion means:
- The Onion Service is served over HTTP, or HTTPS with a self-signed certificate.
A green onion with a lock means:
- The Onion Service is served over HTTPS with a CA-Issued certificate.
A grey onion with a red slash means:
- The Onion Service is served over HTTPS with a self-signed or CA-Issued certificate.
- The webpage contains subresources served over HTTP.
If you cannot reach the onion service you desire, make sure that you have entered the 16-character or, the newest format, 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.
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 a little green onion displaying the state of your connection: secure and using an onion service.
And if you're accessing a website with HTTPS and onion service, it will show an icon of a green onion and a padlock.
Websites that are only accessible over Tor are called "onions" and end in the TLD .onion.
For example, the DuckDuckGo onion is https://3g2upl4pq6kufc4m.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.