What’s the Difference Between Mastodon, Bluesky, and Threads?

The ongoing Twitter exodus sparked life into a new way of doing social media. Instead of a handful of platforms trying to control your life online, people are reclaiming control by building more open and empowering approaches to social media. Some of these you may have heard of: Mastodon, Bluesky, and Threads. Each is distinct, but their differences can be hard to understand as they’re rooted in their different technical approaches. 

The mainstream social web arguably became “five websites, each consisting of screenshots of text from the other four,”  but in just the last few years radical and controversial changes to major platforms were a wake up call to many and are driving people to seek alternatives to the billionaire-driven monocultures.

Two major ecosystems have emerged in the wake, both encouraging the variety and experimentation of the earlier web. The first, built on ActivityPub protocol, is called the Fediverse. While it includes many different kinds of websites, Mastodon and Threads have taken off as alternatives for Twitter that use this protocol. The other is the AT Protocol, powering the Twitter alternative Bluesky.

These protocols, a shared language between computer systems, allow websites to exchange information. It’s a simple concept you’re benefiting from right now, as protocols enable you to read this post in your choice of app or browser. Opening this freedom to social media has a huge impact, letting everyone send and receive posts their own preferred way. Even better, these systems are open to experiment and can cater to every niche, while still connecting to everyone in the wider network. You can leave the dead malls of platform capitalism, and find the services which cater to you.

To save you some trial and error, we have outlined some differences between these options and what that might mean for them down the road.

ActivityPub and AT Protocols

ActivityPub

The Fediverse goes a bit further back,  but ActivityPub’s development by the world wide web consortium (W3C) started in 2014. The W3C is a public-interest non-profit organization which has played a vital role in developing open international standards which define the internet, like HTML and CSS (for better or worse). Their commitment to ActivityPub gives some assurance the protocol will be developed in a stable and ostensibly consensus driven process.

This protocol requires a host website (often called an “instance”) to maintain an “inbox” and “outbox” of content for all of its users, and selectively share this with other host websites on behalf of the users. In this federation model users are accountable to their instance, and instances are accountable to each other. Misbehaving users are banned from instances, and misbehaving instances are cut off from others through “defederation.” This creates some stakes for maintaining good behavior, for users and moderators alike.

ActivityPub handles a wide variety of uses, but the application most associated with the protocol is Mastodon. However, ActivityPub is also integral to Meta’s own Twitter alternative, Threads, which is taking small steps to connect with the Fediverse. Threads is a totally different application, solely hosted by Meta, and is ten times bigger than the Fediverse and Bluesky networks