Open Source Social Media
An account you do not host is a tenant arrangement: the algorithm, the reach, and the suspension button all belong to someone else, and your audience can vanish the moment the terms change. This category answers that in two different ways, which is worth separating before you compare tools. Some projects are social networks you run yourself, where profiles and followers live on a server you or someone you trust controls and federate with the wider network through shared protocols. Others are management tools that keep your presence on the big commercial platforms but let you schedule and publish across all of them from software you own. Open source is what makes either kind auditable and free of per-seat pricing.
Mastodon
Self-hosted, federated social network server based on ActivityPub and open standards
Postiz
Self-hosted AI social media scheduling tool with analytics, collaboration, and public API access
Lemmy
Decentralized link aggregator and forum for federated communities, with self-hosted servers
diaspora*
Privacy-aware, distributed social network with self-hosted pods and open servers
Misskey
Open source, federated social media software for running an ActivityPub microblogging server
Pixelfed
Decentralized photo sharing platform for the fediverse, with no algorithmic feed barriers
Mixpost
Self-hosted social media management for scheduling, publishing, and team workflows on your own server
Friendica
Decentralized social network for federated communication across the Fediverse and other services
Open Source Social Network
PHP social networking software for running your own community site with profiles, chat, groups, and blogs
Our picks
The strong options split by what you are posting and whether you host the network or just manage it.
Federated microblogging network: Mastodon Mastodon is a self-hosted microblogging server that federates across the fediverse over ActivityPub, so your users can follow and be followed by people on other servers and software. It offers chronological timelines, private posts, locked accounts, phrase filtering, and moderation tools, and acts as an OAuth2 provider with REST and Streaming APIs for third-party apps.
Federated forum and link aggregator: Lemmy Lemmy is a federated link aggregator and forum in the style of Reddit, where users subscribe to communities, post links or discussions, vote, and comment across independently run servers. Each server sets its own moderation policy and keeps public moderation logs, and the Rust backend self-hosts with Docker or Ansible, down to a Raspberry Pi.
Federated photo sharing: Pixelfed Pixelfed is a photo-sharing network for the fediverse, built for casual shots and creative photography without algorithmic barriers between you and your followers. Because it speaks ActivityPub, a Pixelfed account can follow and interact with people on other federated services like Mastodon, and it self-hosts, including a one-click YunoHost install.
Cross-platform post scheduler: Postiz Postiz is the scheduler rather than a network, for teams that want to keep posting to the big commercial platforms from software they run. It publishes to X, Bluesky, Mastodon, Instagram, LinkedIn, TikTok, Reddit, and more, adds analytics and team collaboration, and exposes a public API with a NodeJS SDK plus N8N and Make.com integrations.
Sorting the two jobs in this category
The first thing to settle is which job you are actually hiring for, because this category holds two. If you want to run your own social space, the network model matters most: federated servers like Mastodon, Misskey, Pixelfed, and Lemmy exchange posts with the wider fediverse over ActivityPub, which extends reach but brings cross-server moderation and identity questions, while a self-contained site like Open Source Social Network is simpler to govern but harder to grow beyond its own membership. If instead you want to keep posting to the big commercial platforms, Postiz and Mixpost are schedulers, not networks, and belong in a different comparison entirely.
For anything with public signups, treat moderation as core infrastructure rather than an admin afterthought. Social platforms attract spam, impersonation, harassment, and automated abuse in ways most software never sees, so compare reporting queues, role separation, domain blocks, keyword filters, rate limits, and audit trails. Mastodon and Lemmy both expose moderation at the user, post, media, and domain level with public or reviewable logs, which is the kind of granularity moderators need to act consistently under pressure. The best choice is usually the one your moderators can actually operate on a bad day.
Finally, look at the data model and where media lives before committing. Short posts, long-form writing, photo galleries, and video stress storage and background jobs very differently, and media plus queues often cost more to run than the application server. Check how exports work, whether deleted content is purged from local indexes and remote caches, and how the API exposes posts, profiles, and relationships. Because the fediverse copies your posts to other servers, a clean export and a documented protocol are what leave you with a usable archive if you change direction later.
Related categories
Frequently asked questions
What is the difference between the fediverse servers and the schedulers here?+
They solve opposite problems. Servers like Mastodon, Misskey, Lemmy, Pixelfed, and Friendica are social networks you host, giving you profiles, followers, and moderation on your own infrastructure. Postiz and Mixpost do not host a network at all; they schedule and publish posts to existing commercial platforms such as X, LinkedIn, Instagram, and Bluesky from software you run. Decide whether you want to own the audience or just manage posting to it.
How important is federation when choosing a platform?+
Federation matters if you want your users to interact with people on other servers without new accounts everywhere, which is what ActivityPub gives Mastodon, Misskey, Pixelfed, and Friendica. It also adds tradeoffs: remote content can arrive with limited context, moderation differs across servers, and protocol support is not always identical. For a private member space or internal network, federation may add complexity without much benefit.
What moderation features should I check first?+
Look for reporting queues, role-based moderator permissions, account suspension, post and media removal, rate limits, domain blocking, keyword filtering, and audit logs. For a public server you also want signup controls and tools for repeat offenders and coordinated abuse. Lemmy keeps public moderation logs and community and site bans, and Mastodon adds filtering, muting, and reporting, but test how quickly a moderator can understand an incident and act.
Can open source social media replace a mainstream network?+
It can replace parts of the experience but not always the network effect. You gain control over rules, branding, data handling, and community boundaries, and lose automatic access to a huge existing audience, ad tools, and polished creator analytics. The best fit is a community that values ownership and direct membership over maximum reach, which is why federated servers suit niche communities better than mass-market growth.
Will users actually own their data on a federated platform?+
They can, but only if the software and operator support real export and deletion. Check whether users can export posts, media, profile data, followers, blocks, and direct messages in a documented format. The catch is federation: once a post has been copied to other servers, your local deletion controls those copies imperfectly, and quotes, caches, and screenshots elsewhere may persist regardless of your settings.
What security questions matter for social media specifically?+
Focus on account takeover, spam automation, media upload handling, link previews, cross-site scripting, and abuse of federation endpoints if the platform federates. Also check two-factor authentication, session management, rate limiting, and admin audit logs. These systems process untrusted user content all day, so input handling and operational monitoring matter as much as login security, especially on a server open to public registration.
Are native mobile apps usually available?+
It varies by protocol. ActivityPub servers like Mastodon, Misskey, and Pixelfed work in mobile browsers and are reachable by many third-party fediverse apps because their APIs are shared, while single-site software may rely on the mobile web. Before choosing, test posting media, notifications, direct messages, and moderation actions on real phones, since social use is notification-driven and media-heavy and desktop-only workflows frustrate users.