What is Mastodon and how is it different from X?

Mastodon is a federated social network. Instead of one company running one site, thousands of independently operated servers (called instances) talk to each other. A child signs up to one instance, but can follow and message users on others. Each instance has its own rules, its own moderation team, and its own minimum age.

Is Mastodon safer than X/Twitter for teenagers?

It depends entirely on the chosen instance. A well-moderated, general-audience instance can be calmer than X. A small unmoderated or themed instance can be much worse, including instances that exist specifically to host content other platforms remove. Choosing the instance is the single biggest safety decision.

What is content warning (CW) culture?

Many Mastodon users hide potentially upsetting posts behind a tap-to-reveal 'content warning'. This is a community norm rather than a platform feature, and it varies by instance. Some instances are very strict about CWs; others ignore them entirely.

What should I do if there is a problem on this app?

Use the app's in-app report and block tools first - this is usually the fastest way to remove content or restrict an account. If a child is in immediate danger, call 999. For non-emergency police matters, call 101. The NSPCC helpline (0808 800 5000) and Childline (0800 1111) are free and confidential. For a UK reporting decision tree, see /reporting and /tools/reporting-route-finder.

Mastodon Safety Guide for Parents

What parents need to know about Mastodon, the federated social network where the choice of server (instance) shapes the entire safety experience.

Official age

16+

We recommend

16+

Developer

Mastodon gGmbH and independent operators

Risks

Direct messaging

Overview

Mastodon is the most widely used federated social network in the fediverse. Rather than one central service, thousands of independently run servers (instances) interoperate using the ActivityPub protocol. A child who signs up to a generalist instance like mastodon.social is bound by that instance's rules, but their feed can include posts from anyone on any other instance their server still federates with. Each instance sets its own minimum age, moderation policy, and content rules. The flagship mastodon.social instance currently sets a minimum age of 16, but other instances may allow 13+, 18+, or have no age check at all. There is no single parental supervision tool because there is no single platform to supervise.

How children use it

Older teenagers use Mastodon for tech, art, queer, and academic communities, often as a quieter alternative to X. Many discover it through a friend's invite link to a specific instance. Some join hobby-themed instances - art, gaming, language learning, music - which can be tight-knit and well-moderated, while others end up on barely-moderated instances they found through a search or link. Conversation conventions differ sharply: on some instances, content warnings on every sensitive post are expected, while on others CW culture barely exists. Because the experience is shaped by the chosen instance, a child can move from a calm community to a hostile one simply by changing servers.

Main risks

harmful content privacy oversharing cyberbullying social media safety

Recommended privacy settings

Choice of Instance

Location: Sign-up screen -> Choose a server

Set to: Well-moderated generalist instance with a published code of conduct

This is the single most important safety setting on Mastodon. Stick to instances on the Mastodon Server Covenant list for under-18s and avoid any instance that markets itself as 'free speech', 'uncensored', or '18+'.

Default Post Visibility

Location: Preferences -> Other -> Posting privacy

Set to: Followers only

Stops posts appearing on the public timeline of every federated instance. Replies inherit the parent post's visibility, so this is the simplest way to keep a teen's posts from spreading widely.

Discoverability

Location: Preferences -> Public profile -> Suggest account to others

Set to: Off

Prevents the account from being shown in Mastodon's account discovery and search features across instances.

Content Filters

Location: Preferences -> Filters -> Add new filter

Set to: Add keyword filters for adult or distressing topics

Manually filter posts containing specific keywords. There is no built-in adult-content toggle on Mastodon comparable to other platforms.

Direct Messages

Location: When posting -> Visibility -> Direct

Set to: Treat DMs as semi-public

Direct messages on Mastodon are not end-to-end encrypted. Instance administrators on both sides of the conversation can read them. Use only for non-sensitive exchanges.