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Community ForumAlternative to TildesAlternative to Hacker NewsAlternative to Reddit

Lemmy

Federated, open-source link aggregator and Reddit alternative built on the ActivityPub protocol.

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LicenseAGPL-3.0
GitHub stars14.6k
Last commit2 weeks ago
Tags6 topics
CommunityRustFederatedLink AggregatorFediverseActivitypub
Overview

Why consider Lemmy?

Lemmy is a self-hosted, federated link aggregator and community platform similar to Reddit. It uses the ActivityPub protocol to interconnect with other Fediverse instances.

Guided learning

Learn Lemmy by building

Practical setup notes, real use cases, and copy-ready examples in one focused guide.

3 min read 10 sections
In this guide10 sections

What is Lemmy?

Lemmy is an open-source, federated link aggregator and community discussion platform developed with Rust and TypeScript. It operates as a privacy-respecting, self-hostable alternative to commercial link aggregation platforms like Reddit and Hacker News.

Built on the ActivityPub decentralization protocol, Lemmy connects thousands of independently operated community instances (servers) into the Fediverse—a decentralized social network. Users on any Lemmy instance can subscribe to communities on other servers, vote on posts and comments, and interact across instance boundaries without centralized platform ownership.

Who Is It For?

  • Community Builders: Launching niche discussion forums around technology, gaming, news, or hobbies with complete ownership of rules and data.
  • Privacy Advocates: Participating in decentralized social discussion without submitting personal data to advertising-funded platforms.
  • Open-Source Advocates: Running federated infrastructure that cannot be sold, acquired, or shut down by a single corporate entity.

Key Features

  • Federation via ActivityPub: Interconnect with other Lemmy instances and compatible Fediverse platforms (Mastodon, Misskey, Pleroma).
  • Community moderation tools: Moderators can pin posts, remove spam, ban users, and configure community-specific posting rules.
  • Cross-posting and content aggregation: Share links, text posts, and image posts across federated communities.
  • Advanced content ranking with multiple sort modes: Hot, Top, New, Active, Most Comments, and Scaled scoring algorithms.
  • Mobile-friendly apps: Official Lemmy apps plus third-party clients (Jerboa for Android, Voyager for iOS).

Deploying Lemmy with Docker Compose

bash
1# 1. Clone the official Lemmy deployment repository
2git clone https://github.com/LemmyNet/lemmy-ansible.git
3cd lemmy-ansible

Or use the official Docker Compose approach:

bash
1mkdir lemmy && cd lemmy
2wget https://raw.githubusercontent.com/LemmyNet/lemmy-ansible/main/templates/docker-compose.yml
3wget https://raw.githubusercontent.com/LemmyNet/lemmy-ansible/main/templates/lemmy.hjson

Configure lemmy.hjson with your domain name and federation settings:

javascript
1{
2 hostname: "lemmy.example.com"
3 admin_username: "admin"
4 admin_password: "your_secure_admin_password"
5 database: {
6 password: "secure_database_password"
7 }
8}

Start the stack:

bash
1docker compose up -d

Practical Use Cases

1. Technology Community Hub

A tech enthusiast launches lemmy.tech-community.net, hosting curated communities for Rust, Linux, and DevOps discussions — fully federated with other technology-focused Lemmy instances.

2. Local Neighborhood Forum

A city neighborhood association runs a private Lemmy instance for local residents to discuss events, services, and community announcements.

3. Cross-Instance Fediverse Participation

A Mastodon user follows a Lemmy community directly from their Mastodon account, receiving Lemmy post updates in their Mastodon timeline via ActivityPub federation.

Troubleshooting and Limitations

  • Domain and SSL Requirements: Lemmy requires a public FQDN (domain name) with HTTPS for federation to work; configure Nginx with Let's Encrypt before registering with the Lemmy instance list.
  • Federation Delays: Cross-instance federation can take minutes to propagate; remote community subscriptions may lag during high-activity periods.

Official Resources

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Lemmy FAQs

Lemmy is listed as a Community Forum tool on TiloBox. Review the overview, features, and official documentation on this page to decide whether it solves your specific workflow.

Start with the project's GitHub repository and official website for supported installation and deployment instructions. Test the setup with representative data or a small project before rolling it out more widely.

Lemmy is listed under the AGPL-3.0 license. Read the complete license text and the project's notices before using, modifying, or distributing the software.

Production readiness depends on your requirements. Review maintenance activity, security practices, documentation, backup and upgrade procedures, and compatibility with your stack; then validate it in a non-production environment.

Lemmy is listed as an alternative to Tildes. Compare the core workflow, deployment model, integrations, and licensing against your must-have requirements before switching.