Unless you were already familiar with emerging platforms, you likely hadn’t heard of Mastodon until Elon Musk bought Twitter and renamed it X. In the initial aftermath of that acquisition, as users worried about Twitter’s new direction, millions migrated to Mastodon, another microblogging site. Over time, users also tried alternatives like Bluesky or Instagram’s Threads app. But because Mastodon was founded back in 2016, it had years to develop its own identity beyond being just a Twitter alternative.
Mastodon was founded in 2016 by German software developer Eugen Rochko. Unlike Twitter, Facebook, or Reddit, Mastodon is a nonprofit. This means its goal is ideally to benefit the public rather than shareholders.
At first glance, Mastodon might look like a Twitter clone, but the underlying system is far more complex. The service is decentralized, describing itself as a federated network which operates similarly to email.
When you create an account, you choose a server. This is similar to choosing an email provider like Gmail or Yahoo, and it generates your profile address. For example, if you sign up via a climate justice server, your address would be yourusername@climatejustice.social. No matter which server you choose, you can communicate with users on any other server, just as Gmail users can email Hotmail users. However, some servers may block others, preventing communication between them.
Mastodon users generally refer to individual communities as instances or servers. These servers can be run by individuals, groups, or organizations, each with its own rules for signing up and its own moderation policies. Some servers are open to anyone, while others are invite-only or require admin approval. A server for professional scientists, for instance, might ask applicants to link to their research.
Choosing a server might seem stressful, but you can move your account later. You can also follow people regardless of their server.
You may hear Mastodon described as part of the Fediverse, an interconnected web of various social media services. Unlike having separate accounts for Twitter and Instagram, a single Mastodon account can grant you access to other decentralized social networks within the Fediverse.
You may occasionally see Mastodon’s equivalent of tweets called toots, but this term is fading in favor of simply posts. Toot is often found in older third-party clients.
Mastodon supports many Twitter conventions like replies, retweets, favorites, bookmarks, and hashtags. For a long time, Mastodon intentionally avoided a quote-tweet-like feature to discourage dogpiling criticism, but it rolled out that feature in 2025.
Lists work slightly differently; you can only add people to a list if you already follow them. Direct messages on Mastodon are not private messages in a dedicated inbox. They are posts visible only to the users mentioned, provided you adjust the visibility settings.
Mastodon is open source. Anyone can download, modify, and install it on their own server, and the platform’s developers do not own the copyright. However, you must acknowledge the source. Former President Donald Trump’s Truth Social platform initially launched using Mastodon’s code without proper attribution, which Mastodon addressed.
To create an account, visit the Mastodon website and click create account. You will be directed to a page listing servers to choose from, which you can filter by region, language, topic, and sign-up speed. Find a server that interests you and join. If it requires approval, you may need to wait. To simplify the process for new users, Mastodon now offers an easy option to create an account on mastodon.social directly.
Deciding which server to join can be overwhelming. Mastodon’s website has helpful resources, but it’s also a good idea to ask friends for suggestions. You can always change your server affiliation later once you get the hang of things.
You can talk to people on servers other than your own. You can follow people outside your local server and reply to their posts. To follow someone on a different server, you must enter their full username in your server’s search box to find them first.
There are three main timelines. Your Home timeline shows posts from people you follow. The Local timeline shows posts from all users on your server. The Federated timeline shows all public posts from users that people on your server follow. You can enable Slow Mode in preferences to hide timeline updates behind a click if the flow is too fast.
Moderation policy is set by individual server admins. You should read the policy on your chosen server to ensure it aligns with your values.
Compared to Twitter or X, Mastodon’s user base is a tiny fraction of the size. It is also less intuitive to navigate, as it wasn’t designed for a massive global audience. This could change as more developers contribute.
Benefits of Mastodon include that it is not owned by Elon Musk. It is more customizable by nature, with different communities offering varied experiences through their own content guidelines. The smaller user base can sometimes lead to more personal and direct conversations.
Regarding safety, Mastodon is what you make of it. Its decentralized nature allows you to join a server with stricter rules against harassment. Some features are designed to mitigate harassment. For example, you can only search by hashtag, not by arbitrary words in a post. A text-based search can surface posts you’ve written, favorited, boosted, or been mentioned in.
You can post images and video, but support is more limited than on X. You can add up to four images per post, with a file size limit of eight megabytes each. Video and audio can be any length but are limited to 40 megabytes per file.
You can post privately. When writing a post, you can set its visibility to public, unlisted, visible only to your followers, or visible only to users you mention.
There is no universal verification system like on Twitter. Some servers vet user sign-ups, and you can self-verify by adding links with a specific attribute to your profile to prove your identity. Some servers play with the idea informally, like allowing you to add checkmark emojis to your display name, though these carry no official weight.
As of summer 2025, Mastodon has under one million monthly active users and around 10 million registered accounts. It is much smaller than X. Not all social networks are the same, and you might prefer engaging in niche communities on Mastodon, or you might find the system confusing and stay on X, or move to Bluesky or Threads.
If you’re not ready to leave X, you can cross-post using third-party tools like Moa Party or Mastodon Twitter Crossposter. These require authorizing both accounts and setting parameters.
You can find your Twitter friends on Mastodon using third-party tools like Fedifinder, Twitodon, or Debirdify.
Mastodon does not currently work with Bluesky, unless Bluesky chooses to adopt the ActivityPub protocol Mastodon uses, which it is not planning to do. Threads, however, does support ActivityPub. Threads users can choose to share their posts with other ActivityPub servers, including Mastodon.