Mastodon Is the Open Source Twitter Rival You’ve Been Waiting For

If you’ve heard your friends talk about “instances” and “boosts,” they’re probably talking about Mastodon, the nonprofit, open-source social network that’s home to all sorts of communities. This guide will tell you what Mastodon is and why it matters.

What Mastodon Is and Why It’s More than a New Flavor of the Month

Mastodon is a decentralized microblogging platform launched in 2016 by developer Eugen Rochko and run by a German nonprofit. Rather than one central organization controlling everything, Mastodon is a network of independently run servers that speak the same language via something called ActivityPub, which is a part of the World Wide Web Consortium’s web standard.

The model is more akin to email than a single app: your account lives on one server, but you can follow and interact with people on thousands of others. That architecture is attractive to users and institutions who want control and portability. For that reason the European Commission’s EU Voice project, a number of public broadcasters, some universities, and open-source foundations have all played around with Mastodon.

Scale is modest but meaningful. As of the project’s public stats in mid-2025, Mastodon had about 10 million registered accounts and fewer than one million active monthly users. That’s tiny compared to X’s reported 132 million daily actives, but it is large enough to support a lively niche community without the churn of an outrage-driven feed.

Choosing a Server Does Not Have to Be Stressful

Servers (which are frequently referred to as “instances”) are communities, and they have their own rules and moderators. It’s as if they were neighborhoods bordered by common highways. You’ll find lists of communities grouped by interest, language, and region — whether that’s art-centric communities, academic meeting places, and general servers like mastodon.social and mstdn.social.

Don’t overthink your first choice. You can always migrate later with no loss of followers. Some need approval to join; others are free signups. Because each server can block problematic peers, moderation feels more local and accountable than a one-size-fits-all approach.

Getting Started on Mastodon: Finding People to Follow

Onboarding has gotten better since the early “Twitter exodus.” New users are commonly directed to a default server to avoid decision fatigue, with topic-focused directory listings just a mouse click away. Once you sign up, look for people to follow by typing out their full handle in your server’s search box (i.e., @name@server.tld) and tapping follow.

In your Home timeline, you’ll see posts from accounts you follow. The Local timeline shows public posts from your own server. The Federated timeline includes public posts known to your server thanks to its members’ follows. If that firehose feels a bit much, turn on Slow Mode in Preferences to batch updates and make the feed more manageable.

Discovery works differently by design. There is no full-text search across all posts; hashtags are the main discovery tool. Tag your posts if you want them to be found, and search tags to find active conversations.

Familiar Features and What’s Different on Mastodon

The platform supports replies, favorites, bookmarks, and boosts (retweeting on Mastodon). Quote posts, long discussed as a mechanism that could enable pile-ons, were introduced in 2025 with UX cues to avoid harassment. Lists are there, though you can add only people with whom you’re already on social terms, a tweak that dramatically reduces drive-by surveillance.

Direct messages are basically just limited-visibility posts: you address them to @user and set the visibility to “mentioned only.” Think of them as private but not secret — any admin on either side can look at them for the purposes of moderation.

Privacy controls are by post: public, unlisted (public but excluded from discovery features), followers-only, mentioned-only. Media allowed are images (up to 4, typically around 8MB each) along with video and audio, for which a typical instance limit would be around 40MB. Accessibility is excellent: alt text is encouraged (and on some servers, required), and content warnings are a cultural norm for triggering topics, spoilers, and real shit.

Safety, Moderation, and Verification Across Servers

Moderation is in the hands of server admins, so norms vary — and that’s some of the point. Choose an instance with explicit rules of engagement, fast response times, and transparent enforcement. You can also mute or block what you don’t like, as well as entire domains, and filter out content containing a keyword, the name of a specific user, or a domain; media can be collapsed by default.

There’s no global blue check. Mastodon supports “rel=me”-based verification: you can add links to a website you control, verify them, and display a verified badge next to those URLs. This method is employed by many journalists, academics, and nonprofits who want to signal authenticity without being charged a platform fee.

Moving In from X or Threads and Rebuilding Your Follows

You can regrow your social graph with the help of community tools that sift through who you follow elsewhere and look up their Mastodon handles.

Some popular choices mentioned by our readers are Fedifinder, Debirdify, and Twitodon. For cross-posting, tools like Moa Party or Mastodon Twitter Crossposter allow you to replicate updates with more granular rules.

Threads has started to federate some content over ActivityPub, which means that a Mastodon account can follow timelines made by Threads profiles as the feature rolls out. Bluesky, on the other hand, is based on its own protocol and is not currently interoperable — unless that changes.

Pro Tips to Help You Make Yourself at Home

Use hashtags purposefully; they’re the discovery engine. Write descriptive alt text so that your posts can travel beyond your intended audience and still be accessible. For trusted apps in your platform of choice, see some examples for mobile and desktop that provide features like multi-column views, scheduling, and robust filters that match or best what you’re accustomed to elsewhere.

Create filters for hashtags that catch your eye, plug in or create lists to filter the content you see, and consider a smaller instance if hands-on moderation matters and local chat adds value. If your needs shift, migrate; your followers can follow.

Bottom Line: What Mastodon Offers and Why It Matters

Mastodon trades the influence and scale of a global watercooler for control, portability, and healthier norms. It takes a day to learn, but once you get it — and servers, visibility, and hashtags seem the internet equivalent of skinning a dead elk — it just feels so human. If you’d love to see what it looks like when a social network is accountable to its users (not advertising targets), Mastodon is waiting for you.