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Discourse (self-host) vs Lemmy

Self-host pick — both replace Reddit (Threaded community / forum).

Both Discourse (self-host) and Lemmy self-host as a replacement for Reddit (Threaded community / forum). Pick Discourse (self-host) if you want a GPL-licensed codebase (GPL-2.0); pick Lemmy for AGPL (AGPL-3.0). Both run in roughly the same cost bracket — $10-20/mo vps — discourse needs at least 2gb ram and external smtp; mailgun/postmark/resend handle the email cost line vs $5-10/mo vps for a small instance; storage scales with image uploads.

Discourse (self-host)open-sourceLemmyopen-source
LicenseGPL-2.0AGPL-3.0
Setup time30min — official `discourse_docker` standalone install30min docker-compose (Rust backend + Postgres + UI + pict-rs for images)
Monthly cost$10-20/mo VPS — Discourse needs at least 2GB RAM and external SMTP; Mailgun/Postmark/Resend handle the email cost line.$5-10/mo VPS for a small instance; storage scales with image uploads.
GitHubdiscourse/discourse ★ 47.0k · last commit todayaliveLemmyNet/lemmy ★ 14.4k · last commit todayalive
ReplacesReddit + 1 otherReddit

Good fit for

Discourse (self-host)

Long-form communities, support forums, and mature subreddits that ran more like discussion boards than link-aggregators.

Weak at:Not a vote-ranked link aggregator — the front page is chronological, not algorithmic.

Lemmy

Communities that want a Reddit-shaped federated home and value the upvote/downvote ranking model.

Weak at:Mobile clients are improving but inconsistent; smaller global reach than Reddit's network effect.

In a terminal? npx -y github:SolvoHQ/os-alt-cli reddit prints Reddit's self-host options including both — how the CLI works →

FAQ

Which is easier to self-host, Discourse (self-host) or Lemmy?

Discourse (self-host): 30min — official `discourse_docker` standalone install. Lemmy: 30min docker-compose (Rust backend + Postgres + UI + pict-rs for images).

What does each cost to run?

Discourse (self-host): $10-20/mo VPS — Discourse needs at least 2GB RAM and external SMTP; Mailgun/Postmark/Resend handle the email cost line.. Lemmy: $5-10/mo VPS for a small instance; storage scales with image uploads.. Both projects are free and open source.

Do Discourse (self-host) and Lemmy replace the same SaaS?

Yes — both are open-source alternatives to Reddit.