Misskey is an open-source, ActivityPub-based microblogging platform from Japan. It joins the wider fediverse while adding reactions, channels, antennas and several timelines, which makes it more customizable than many comparable servers.
Readers new to the wider network can start with the fediverse overview, then return here for the specifics of this platform.
Where Misskey came from
According to Wikipedia’s Misskey article, the project began as a BBS-style internet forum built by high school student Eiji Shinoda in 2014. It later grew into a federated social platform. The same article notes that the name comes from the lyrics of a song by the Japanese singer May’n.
Misskey is open source and licensed under the AGPLv3, and it is developed with Node.js. The AGPL matters for a networked service: anyone who modifies the code and runs it for others is expected to share those changes. That has encouraged a steady supply of forks and community variants.
Wikipedia also describes an unusual stance: despite being decentralized, Misskey is not philosophically opposed to centralization. In practice this shows in how large the flagship server has become, as covered below.
Core features of a Misskey server
The official Misskey Hub presents the platform as one that implements ActivityPub, the protocol behind much of the federated social web. Its feature list is the clearest summary of what sets the software apart.
Notes, reactions and privacy
Posts on Misskey are called notes. Per Wikipedia, notes can be reposted either on their own or with an added quote note, and they have customizable privacy settings that control who can see them. The Hub highlights reactions, which let users respond to a note with an expressive emoji instead of a plain like.
Channels, antennas and Drive
- Channels let a server build communities around specific topics, which gives it some forum-like structure.
- Antennas create timelines that collect only notes containing specific keywords.
- Drive gives users a dedicated interface for managing uploaded files.
These tools make the software feel closer to a personal dashboard than a single feed. Users can build their own filtered views instead of relying on one stream.
Multiple timelines
Wikipedia explains that Misskey offers several timelines, each shown in reverse chronological order. The Home timeline shows notes from followed accounts. The Local timeline shows notes from the instance in use. The Social timeline combines the two, and the Global timeline covers every public note the instance knows about. Choosing between these views gives users control over how much of the wider network reaches them.
Federation and performance
The Hub states that implementing the open ActivityPub protocol allows interaction not just with other Misskey servers but with any software that supports it. Servers running Mastodon, for instance, can exchange notes with Misskey servers, though features such as reactions may display differently across software.
The Hub also names two performance features built on Redis. Fan-out Timeline Technology builds timelines on Redis to improve performance, and Reactions Buffering Technology caches reaction data on Redis for the same reason. These matter most for busy servers where many users react to the same notes.
Users comparing federated projects may also want the profile of pleroma, another microblogging server with a different design emphasis. Those who want threaded, community-style discussion rather than microblogging can look at lemmy, which covers link aggregation on the fediverse.
Growth, funding and the forks
The largest Misskey server is Misskey.io. Wikipedia reports that as of February 2024, over 450,000 users were registered there, and that the server is crowdfunded. Its administrator is a Japanese system administrator who goes by Murakami-san.
Registrations on Misskey.io rose rapidly in mid-2023, and other Misskey servers also saw signup spikes. In response, the art-sharing platform Skeb announced on July 14, 2023 that it would sponsor the Misskey development team. In early 2024 the project was targeted by a spam attack that used Mastodon instances with open registration, according to the same source.
Misskey has also spawned forks. Firefish, which added stronger Mastodon API compatibility, was discontinued because of a lack of maintainers and code quality issues. Other forks include Foundkey and Catodon. A fork is a separate project, so features and federation behavior can differ from upstream Misskey.
A federation debate
Wikipedia records that in November 2025, Misskey.io’s administrator announced intentions to replace ActivityPub with Misskey’s own low-overhead federation system in “a few years”. Shinoda later said that this was “fake news”. As of that source, no replacement had been confirmed, so anyone relying on ActivityPub compatibility should check the project’s current announcements.
Who Misskey suits
Misskey tends to fit users who value customization: custom timelines, keyword antennas, expressive reactions and channels. Server operators gain an AGPL codebase and Redis-based performance tools. People who want the simplest possible interface, or the widest app ecosystem, may find other fediverse software easier, and the right choice depends on the community a user wants to join.
For everyday users
A newcomer usually joins an existing server rather than running one. The choice of server shapes the experience more than the software does: the Local timeline reflects that server’s own community, while the Global timeline reflects whatever its neighbors have federated. A server with a clear focus tends to produce a more coherent Local feed, and antennas can then narrow the stream further to the topics a person actually follows.
Reactions change the tone of interaction. Instead of a single like button, a note can collect many different emoji responses, so a reply of appreciation, amusement or sympathy can be expressed without writing a comment. Because other fediverse software handles these differently, a reaction sent to a non-Misskey server may appear as a plain like or not at all, depending on what the receiving software supports.
For server operators
Running a server means taking on moderation, storage and updates. Drive keeps uploaded media organized for each user, but operators still decide how much storage to provide and who may register. The spam attack of early 2024, which abused open registration on Mastodon instances, is a reminder that open signups invite abuse on any platform in the network. Operators who rely on the Redis-based timeline and reaction features should plan for that component as part of their hosting setup.
Because the code is AGPL-licensed, operators who customize their server are expected to make the modified source available to its users. This is one reason the ecosystem has produced several variants, and operators should check each fork’s maintenance status before building on it. The discontinuation of Firefish shows that a fork can lose its maintainers, leaving its users to migrate.
Reading the project’s direction
Misskey’s development is closely tied to its Japanese community, and the sponsorship from Skeb in 2023 shows how outside organizations can fund the work. Funding, a crowdfunded flagship server and public code give the project several sources of stability, though none guarantees a particular roadmap. Announcements about federation changes are best confirmed with the project’s own channels, particularly after the November 2025 episode in which a reported plan was later dismissed by the lead developer as “fake news”.
Frequently asked questions
What is Misskey?
Misskey is open-source microblogging software that implements ActivityPub, so its servers can connect to the fediverse. It was started in 2014 by Eiji Shinoda.
Is Misskey free?
Yes. The source is open and licensed under the AGPLv3, according to Wikipedia. Individual servers may be funded by donations or crowdfunding, as Misskey.io is.
Can Misskey talk to Mastodon?
Yes. Because Misskey implements ActivityPub, it can interact with any software supporting that protocol, as the Misskey Hub states.
What are antennas?
Antennas are timelines that collect only notes containing specific keywords, per the Misskey Hub.
