Content Moderation on Mastodon: How It Works and What You Need to Know

Mastodon offers a refreshing alternative to mainstream social media platforms, but its decentralized nature also means that content moderation works differently compared to centralized sites like Twitter, Facebook and co. Instead of one company enforcing global rules, Mastodon relies on individual instances to set and enforce their own guidelines.

How Moderation Works on Mastodon

Each Mastodon instance (or server) is independently operated and has its own moderation policies, which are typically outlined in the instance’s terms of service and/or community guidelines.

1. Instance-Level Moderation

Mastodon’s approach to moderation is based on local control. Instance administrators and moderators can:

Set community guidelines and rules that reflect their values and goals.
Suspend or ban accounts that violate their rules.
Filter or block content based on specific topics or keywords.
Limit or remove the visibility of certain posts within their instance.

Because of this, some instances may allow content that others prohibit, leading to differences in user experience across the Fediverse.

2. Federation and Moderation Between Instances

Since Mastodon instances communicate with each other, moderation doesn’t stop at the local level. Instances can:

Block (defederate) other instances if they host content that violates their policies (e.g. hate speech, harassment, spam).
Restrict interactions with certain servers by limiting content visibility or user engagement.
Warn users when an instance has a bad reputation or lacks moderation.

This means that some content or users from one instance may not be visible to those on another, depending on the moderation decisions of instance administrators.

3. User-Level Controls

Mastodon also empowers users with several moderation tools to customize their experience:

Mute or block users – Hide posts from specific accounts.
Block an entire domain – Users can block an entire domain for themselves, this will removes follows and followers from the blocked domain. Old posts can be seen and interacted with by users of the blocked domain.
Filter out specific topics and words – Use content filters to avoid certain discussions.
Report content – Flag problematic posts to instance moderators.
Adjust visibility settings – Choose who can see your posts (public, followers-only, or unlisted).

Challenges of Mastodon’s Moderation Model

While Mastodon’s decentralized approach provides more control and flexibility, it also comes with challenges:

Inconsistent moderation – Since each instance sets its own rules, enforcement can vary widely.
Defederation can fragment the network – If instances block each other too aggressively, it can limit connectivity between communities.
Moderation depends on volunteers – Many instance admins are unpaid and may struggle with handling large-scale moderation.

Final Thoughts

Mastodon’s moderation system reflects its core values of community-driven governance and user autonomy. While it may not be as centralized or uniform as mainstream social media, it offers a more tailored and transparent approach to content moderation.

For users, choosing the right instance with policies that align with their expectations is key. And for administrators, balancing freedom with responsible moderation remains an ongoing challenge in the evolving world of decentralized social media.

And the Fediverse is open. With that can everybody create their own instance and setup their own moderation guidelines and rules. The basic standard is that a user has the right to free speech but not the right to free audience.

Curious about how it works? Join an instance and experience Mastodon's unique moderation in action! 🚀

If you want to hear more from me you can find me in the Fediverse at @gelbphoenix@social.gelbphoenix.de (Mastodon) or @gelbphoenix@gram.social (Pixelfed).