Keith’s Belated Guide to Mastodon (for Twitter Exiles)

There are a ton of “what is Mastodon” or “getting started with Mastodon” or “what is this Mastodon thing, really?” articles out there already, but this is my blog and I wanted to write my own guide, so here we are. Let’s go!

What isn’t Mastodon

Mastodon isn’t Twitter. Let’s get that right out here to start with – in fact, let’s say it again, but louder: Mastodon isn’t Twitter. It has a lot of things in common with Twitter, but if you don’t accept the fact that it is NOT Twitter, then we aren’t going to get anywhere.

So say it with me one last time: Mastodon is not Twitter.

What is Mastodon?

Officially, Mastodon is a “decentralized social media network that is part of the Fediverse of services that use the open ActivityPub protocol.” But unless you’re an enormous geek (like me) that probably doesn’t tell you much.

I like to say that Mastodon is kind of like a hybrid between a microbloging service (like Twitter) and web mail (like Gmail).

It’s like (but not identical to) Twitter in the sense that it has features like timelines, lists, accounts that start with an ‘@’ symbol, hashtags, DMs, and a lot of people use it to post pictures of cats.

There are other superficial similarities to Twitter. Whereas Twitter has “Tweets,” Mastodon has “toots” (or just “posts” as they are called, now that the creator – who is not a native English speaker – realized that “toot” has another meaning in English besides the sound an elephant – or mastodon – makes with its trunk). Instead of retweeting, you “boost,” and there is no equivalent to a quote-retweet (for what I think are valid reasons, although this is something that is still being debated).

On the other hand, it’s like webmail in the sense that you have to sign up with one particular provider or another, but once signed up you can send messages to anyone, regardless of where they signed up. Like email, you have to include the domain name in someone’s full user name (so it’s, instead of just @user). Like email, you can have accounts on as many servers (or “instances” as they’re called in Masto-speak) as you like, although there’s not really any good reason to do so. And again like email, if you want to you can just run your own instance for yourself if you want to have total control.

How do you use Mastodon?

You can use Mastodon from a web interface or from an app. Because it’s open source, there are no restrictions on who can write an app – and as a result there are a ton (a Masto-ton? ha, ha) of options. But by and large the most popular ones mimic the best Twitter apps (here’s looking at you, Tweetbot) or the professional Twitter tools (e.g., Tweetdeck).

Using it is a lot like using Twitter (but not identical). There is more nuance over who can see your posts – you can make them public, unlisted, visible only to those who specifically follow you, or mention-only (so only people you specifically mention in the post can see it). And you can change this on a post-by-post basis; you don’t have to make your entire account private to post something private. You can also block people if needed, just like on Twitter.

Post can also be marked as “containing sensitive content,” where you can add a content-warning, which is a nice touch, and you can do the same to any photos you post. But if you don’t care about this, you can also enable an option to make these kinds of posts visible (to you, while you’re logged in) by default. The options for adding alt-text to images is also generally a bit better than on Twitter, with adding alt-text being more encouraged.

The post character limit is, by default, 500, but even this isn’t a hard-and-fast rule – but we’ll get back to that.

One big difference is that there are more than just the 2 timelines (your timeline and the public timeline) that Twitter has*. In Mastodon, you have your timeline – which just like Twitter shows all activity from people you follow. But there is also what is called the “local” timeline, which shows all posts by everyone on the same instance as you. And then one step up from that is the “federated” timeline, which shows all posts by everyone on every instance that is connected to yours (which generally means everyone using Mastodon, but not quite, and I’ll get back to this as well – I promise).

Local what now?

One of the benefits of Mastodon is that instead of being one giant chat room where everyone in the entire world is talking over one another, Mastodon is a bunch of smaller rooms that are connected to one another. As a result, when you sign up and choose an instance, you can choose one that has people talking about things you like, and your local timeline on that instance will be just those people. And you can still hear what everyone in other rooms is saying, if you want to – the best of both worlds!

Now, in reality it isn’t that simple – people rarely have just 1 interest or only talk about just 1 thing, even if they signed up to an instance specifically about 1 topic – and most instances tend to be on the “general” side anyway… but still, there’s a benefit to having multiple, smaller instances instead of just 1 massive, monolithic one.

For one thing, moderation is easier – since the mods only have to watch their local instance. And since instances tend to be smaller, it’s easier for mods to watch out for bad behavior without having to resort to algorithms or automated systems (which always fail).

What is this Fediverse thing, anyway?

Ah, now we come to the crux of the discussion. The Fediverse is just a way of referring to all the servers and services that are using the ActivityPub protocol to talk to one another and exchange data. It’s a bit like if instead of calling it “email” we had called it “the electronic messsage-verse.”

The key thing to know here, though, is that ActivityPub is just a protocol – and Mastodon is just one program/service that uses it.

Mastodon has a 500 character limit, but the ActivityPub protocol does not. So other services that use ActivityPub could create posts that have as many characters as they like. And – most interesting of all – if these services are linked up into the Fediverse, anyone on any one of these services can see posts made by anyone else.

It’s a bit like if you were on Twitter but you could follow someone’s account on, say, Facebook, or Instagram, and their posts would just show up in your Twitter feed – even though those posts might be something Twitter doesn’t allow – such as a massive essay of thousands of characters, or a video reel, or whatever.

Now this seems kind of crazy – and in a way, it is, but it’s also kind of crazy cool, if you think about it. Using Mastodon, you could follow people who make posts just like on Twitter… and also follow artists posting photos or artwork on a service specifically for that which happens to use ActivityPub… and also follow a writer who is making infrequent, but long-form content articles (like, say, full blog posts like this one)… and all this would just appear in your feed!

This is what makes Mastodon so neat, and what makes huge nerds like me get excited over it.

Trade-offs, always trade-offs

Mastodon is not all sunshine and roses, of course. It is a relatively new service (as far as these things go) and so it is having a lot of growing pains, especially as people leave (escape) Twitter and look for a replacement. And because Mastodon is, as I have said multiple times, NOT Twitter, some of these people get upset or confused by this.

And some of this confusion is understandable. Mastodon, by virtue of being so flexible, is more complicated than just creating an account at and starting to spam pictures of your cat. There are a lot of instances, and it’s not always easy to choose one – and instances are run, generally, by individuals or small organizations, so sometimes they fail or just up and vanish – taking all of your cat photos brilliant observations with them. (I know this last one from personal experience.)

Searching is also complicated due to the fact that there’s no one central instance – you can search by hashtag, but not by any old text. Though this does have the advantage that randos can’t just butt in on you and “well, actually…” their way into your conversations just by searching for certain topical words or phrases you might be using.

There’s also the fact that instances can be cut off from one another – the “federation” part of the “Fediverse” only works if the connection is both ways, and if an instance misbehaves (maybe by trying to spread spam or viruses or just being really, really rude) other instances may choose to sever ties with it – eventually isolating it and cutting it off from the rest of the Fediverse.


Mostly, I think that as long as you understand that (say it with me) Mastodon is not Twitter, and that it is all built on top of an open protocol that any application or service can use to expose content to the wider “Fediverse,” then you will have a good experience with Mastodon. It has its ups and downs, just like anything (including Twitter), but overall I think it’s a pretty good attempt and making a social network and increasing connections between people and letting them express themselves however they like. (Kind of like how I’m doing here in writing this guide.)

^ Yeah, I know that technically Twitter lists can function like timelines, making it 3 timelines on Twitter as well… but Mastodon can do that, too, and anyway who’s counting?

By Keith Survell

Geek, professional programmer, amateur photographer, crazy rabbit guy, only slightly obsessed with cute things.