Threads ActivityPub Federation Explained for First-Time Users

You may have heard that Threads can connect to other social networks like Mastodon. This is possible because of a technology called ActivityPub. ActivityPub is a standard protocol that lets different social platforms communicate with each other. It means you can post on Threads and have those posts appear on other services that also support ActivityPub. This article explains what ActivityPub federation is, how Threads uses it, and what you need to know as a first-time user.

What Is ActivityPub and How Does Threads Use It?

ActivityPub is a decentralized social networking protocol. It was created by the World Wide Web Consortium, the same group that maintains HTML and CSS standards. The protocol defines how servers exchange user data, posts, and interactions like likes and replies. When a platform supports ActivityPub, it can talk to any other platform that also supports the protocol. This network of interoperable services is often called the fediverse.

Threads implemented ActivityPub support in March 2024. This means Threads is now part of the fediverse. When you enable federation on your Threads account, your public posts become visible to users on other ActivityPub services such as Mastodon, Pleroma, and PeerTube. Those users can follow your Threads profile, see your posts in their home feeds, and reply to them. Their replies appear as replies on Threads as well.

Key Federation Features in Threads

Federation in Threads is not automatic. You must turn it on in your account settings. Here are the main features:

• Public posts only: Only posts you mark as public are shared. Posts set to “Followers” or “Mentioned Only” remain inside Threads.
• Profile visibility: Your Threads profile becomes discoverable on other fediverse services. Other users can follow you from Mastodon or similar platforms.
• Interaction sync: Likes, replies, and reposts from federated users appear on Threads. You see them in your notifications and on your posts.
• No direct messages: ActivityPub does not support direct messaging in Threads. Private conversations stay inside the Threads app.

Steps to Enable ActivityPub Federation on Your Threads Account

Before you start, make sure your Threads account is public. If your account is private, federation cannot work because private accounts do not share public posts. Also, verify that your Threads app is updated to the latest version. Federation settings appear only in version 300 or newer.

1. Open the Threads app
   Launch Threads on your iOS or Android device. Log in if you are not already signed in.
2. Go to your profile
   Tap the profile icon in the bottom-right corner of the screen. It looks like a person silhouette.
3. Access settings
   Tap the two horizontal lines in the top-right corner. Then tap Settings.
4. Navigate to Privacy
   In the Settings menu, tap Privacy. This opens your privacy controls.
5. Find Fediverse sharing
   Scroll down until you see Fediverse sharing. Tap it.
6. Toggle federation on
   Tap the toggle switch next to Fediverse sharing to turn it on. A confirmation dialog appears. Read the information and tap Turn on.
7. Verify the change
   After enabling, you see a green indicator next to Fediverse sharing. Your public posts are now federated.

Once enabled, it may take a few minutes for your profile to appear on other fediverse services. You can test this by searching for your Threads profile from a Mastodon instance. Use the search format @username@threads.net.

Common Misconceptions and Things to Avoid

“Federation means my private posts are shared”

This is false. Federation only applies to public posts. Posts set to “Followers” or “Mentioned Only” remain inside Threads and are not sent to other servers. Your private account is not federated at all.

“I lose control over my content once federated”

No. You retain full control. Deleting a post on Threads removes it from the fediverse as well. The protocol sends a delete command to all servers that have a copy. However, other servers may cache content temporarily. This is similar to how web browsers cache pages.

“I need a separate account on Mastodon to use federation”

You do not. Federation works automatically through your Threads account. Other users on Mastodon or Pleroma can follow you without you creating an account on their platform. Your Threads profile acts as a bridge.

“Federation slows down the Threads app”

Federation happens in the background. It does not affect app performance. The Threads app processes interactions from other services just like it processes interactions from Threads users. You will not notice any difference in speed or responsiveness.

Threads vs Mastodon: Federation Approach Compared

Item	Threads	Mastodon
Federation activation	Manual toggle in settings	Automatic by default
Post visibility control	Public, Followers, Mentioned Only	Public, Unlisted, Followers Only, Direct
Direct messages via ActivityPub	Not supported	Supported
Account portability	No export of followers	Full account migration supported
Server choice	Only threads.net	Many independent instances

Threads uses a centralized server model, while Mastodon is fully decentralized. This means Threads controls the software and rules. Mastodon users can choose any instance with its own moderation policies. Both services use the same ActivityPub protocol, so they can interoperate despite these differences.

Federation on Threads is a one-way street in some aspects. Threads users can follow Mastodon accounts, but only if the Mastodon account is public. Mastodon users can follow Threads accounts only after the Threads user enables federation. This asymmetry exists because Threads is still building out its full ActivityPub support.

Now you understand what ActivityPub federation is and how to enable it on Threads. Try enabling the Fediverse sharing toggle in your Privacy settings. After that, search for your profile on a Mastodon instance to confirm it appears. For a deeper test, ask a friend on Mastodon to follow you and reply to one of your public Threads posts. This will confirm that the federation is working in both directions.