tech Uncategorized

Mastodon: Into the Fediverse… a Tootorial.

Mastodon: Into the Fediverse… my new blog about moving to the open-source Tw*tter alternative everyone’s talking about. #caschat #EduTwitter #EduTooter

As author of “How to Teach Computer Science” (see how early I got the plug in?) it’s probably right that I post about my foray into Mastodon, the “Twitter alternative” that everyone is talking about (again, more on that later). I will try to keep this post updated over the next few weeks so check back often. If you like this post, consider bunging me a coffee or buying my book. Also forgive the occasional ads on the page, this is not my day job. Thanks!

Screenshot of the Mastodon web interface showing the author's profile and a post below giving the look and feel of the website.

What is Mastodon?

It’s microblogging software, running on thousands of separate servers. You sign up and can share posts or “toots”, that others can see. You can follow people and use hashtags, much like Twitter (and also very much not like Twitter in all the right ways, which you will understand soon).

In short, it’s software. It’s not a service/website/platform/publisher like Twitter. It has no teams of content moderators. This vital distinction is of utmost importance, because it’s underlies many complaints made by new users, who have made the switch from the birdsite. Essentially, Mastodon is software that runs on a server and provides a microblogging platform to its users. A technical person called a “sysadmin” has installed the software on a server and made it available to you via the WWW. That sysadmin is wholly responsible for the server “instance” they have created. Users sign up on the web interface through a normal browser, or on a mobile device can download the Mastodon app, or alternative apps like Tusky.

Note: I will use the terms “server”, “instance” and “domain” interchangeably in this post because if you’re new to the service the distinctions are really not important.

Each instance exists independently of the others and should be considered a separate community, with its own rules and etiquette, although they do talk to each other (see later). Take the time to learn those rules because the premise of a Mastodon instance is that it is a collaborative, supportive community of like-minded people, with no agenda, no ads and no algorithms pushing content. Just like the early internet servers were, on Fidonet, Usenet, IRC and everything else that used this model long ago! (Aside: I was sending emails and using Usenet in 1986 at Sheffield Uni. I’ve seen these services come and go a few times. More on that later).


Which server do I choose?

You’re probably here because someone you know has suggested you join mastodon. So maybe join the server they are on. If they have shared their full mastodon username, the server is the bit after the username, i.e. my full username is so my server is available on the web at If that server is closed to new signups (the number of people signed up across the “fediverse” has doubled in the last week) then go with a similar one, and you can start looking here.

I am on whose server rules can be found at the “about” page here and you can see the rules listed as follows:

  1. Sexually explicit or violent media must be marked as sensitive when posting.
  2. No spam or advertising.
  3. No racism, sexism, homophobia, transphobia, xenophobia, or casteism.
  4. No incitement of violence or promotion of violent ideologies.
  5. No harassment, dogpiling or doxxing of other users.
  6. No illegal content.

That all sounds great, but even more information is below the rules. I can see over 100 other instances that are banned from connecting to this instance, and read the reasons for doing so. “Racism”, “illegal content”, “harassing trans people” and “conspiracy theories” are some of the reasons listed by @stux, my sysadmin for preventing other servers from connecting to this one. Stux is a good guy who runs this site for a living, so I have PayPalled him some money. Your server admin can be found on your server’s “about” page, and you should consider helping because they usually run the site purely on voluntary donations.

Browsing the about page will make the culture of this instance clear to you, and reveal the outlook of the sysadmin(s) which is kind of important, so you can decide whether you want to join the community.


What’s “federation”?

So each instance behaves like a community, but that’s no good if your friends are all on other instances, right? OK that’s where federation comes in. Each instance will “federate” with all other instances: you can follow others and your posts will be seen by others on other instances and vice versa, within certain parameters. We saw above that a sysadmin will judiciously block other servers based on their federation policies, and that’s great to keep this instance reasonably safe. But generally speaking, your instance will seamlessly talk to all other instances where your friends are. Here is a handy flowchart to show how federation works, courtesy of user :

Diagram showing "public toot by @Foo" at the top and a flowchart below explaining which timeline a toot will appear.

How do I find people to follow?

Start with someone you know, and browse to their profile. I am here: . If you click “following” and “followers” you can see who I follow, and quickly follow them using the little “add person” icon to the right of their names:

Icon of person and plus sign overlaid

You can also search hashtags, and if you’re reading this because you are in my UK teaching network, you probably want to click here and follow some people posting with the #EduTooter hashtag. Just type #EduTooter into the search box on the site or app, and then follow some of the tooters that come up! (Sorry about the word “toot”, I thought “tweet” was silly, but here we are…)

Trying hashtags like #medicine, #grungemusic #crossstitch usually comes up with some people to follow, but this process may be slow and take a few weeks before your timeline is as busy as the birdsite was. Bear with it, this is because there is no algorithm pushing content to you, which is why you came here, right? To be free of the corporate firehose of questionable information? Right?

Note: Mastodon has a “Lists” feature just like the birdsite, so check that out, when I have any useful lists of EduTooters to share I’ll share them here, come back often!

Can I use an app?

Yes. I recommend signing up through the web browser interface, it’s just much easier to get started that way. Some features are not available on the app and the screen real-estate needed to get set up easily is substantial. But once signed up, there is an “official” (i.e. provided by the not-for-profit German company that looks after the Mastodon open-source software) app called Mastodon but also some “unofficial” ones. I’m trying Tusky now and running both apps to check them out. Others may be available.

How do I stay safe?

You have checked the moderation policies of your server instance, right? So you know what content is allowed and what isn’t. Firstly, be a good member of the community and follow those rules yourself. Be careful, many server rules require Content Warnings for certain things, e.g. requires a CW before mentioning violence. Just add a CW in the app or on the web by clicking “CW” below the text box. Follow all the other rules as well, to be a good community member. (This is how the early internet was, let’s recreate the good times of community!)

If you get harassed, attacked or any trouble, you need to know how to block a user, block a domain or report to the admin. Click the 3-dots on the right of the action icons below the toot. In the pop-up menu, choose an action from Mute, Block user, or Block domain. Obviously “block domain” will be greyed out on your own domain.

Screenshot of Mastodon timeline after clicking on the 3 dots, showing the pop-up menu with Mute and BLock options highlighted.

(I’m grateful to Alex for the image – follow him here).

How do I support my sysadmin?

Remember, Mastodon is run by volunteers. I’ve written about my host above and explained that I have sent a donation by PayPal to @Stux, many of you may be on which is run by the lead developer of the Mastodon software, Eugen aka @Gargron. Whichever server you are on, you should definitely support your admin with a small payment: whatever you can afford, as this ensures the platform remains usable, and stays out of the hands of the big corporations. Click the “About” page on your server home page to find out how to help.

Where can I find out more?

In writing this blog I am grateful to Max Eddy for his article in PCMag How to Leave Twitter for Mastodon which is great further reading.

Wired has some tips in this article: “How to find your friends on Mastodon”

Mashable has an article here also “How to Switch Mastodon for Twitter”.

If you enjoyed this blog or found it useful, remember I too rely on donations! I wrote two books called “How to Teach Computer Science” and “How to Learn Computer Science” available here, if you have a child aged 14-21 learning computer science, why not get them a copy of the latter? Or you can buy me a coffee below. See you on Mastodon!

If you are grateful for my blog, please buy me a coffee at, thanks!

By mraharrisoncs

Freelance consultant, teacher and author, professional development lead for the NCCE, CAS Master Teacher, Computer Science lecturer.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s