How do I self-host Mastodon on a VPS?

What does a Mastodon server run?

Five services, which a small instance keeps on one VPS:

• mastodon-web: Puma, serving the web interface and the REST API (Ruby on Rails).
• mastodon-sidekiq: background jobs such as deliveries to other servers, media processing, notifications and mail.
• mastodon-streaming: the Node.js streaming API behind live timelines.
• PostgreSQL: the main database.
• Redis: cache and job queue.

The README of Mastodon 4.7.4, released on 29 October 2026, lists Ruby 3.3+, PostgreSQL 14+, Redis 7.0+, Node.js 22+ and FFmpeg 5.1+. The official install guide targets Ubuntu 24.04 and Debian 13, and both are images you can pick at checkout: Debian 13, Debian 12, Ubuntu 24.04 LTS, Ubuntu 22.04 LTS, AlmaLinux 10, Rocky Linux 10. nginx sits in front of everything and serves the static files.

Which domain settings can never change?

LOCAL_DOMAIN, the domain in every handle. Mastodon's configuration reference says it cannot be safely changed later: other servers would treat your existing accounts as new ones. Choose it before the setup wizard runs.

WEB_DOMAIN is the option for handles on one domain and the server on another. With LOCAL_DOMAIN=example.com and WEB_DOMAIN=mastodon.example.com, users are @[email protected] while the site runs on the subdomain. The main domain must then redirect /.well-known/webfinger to the Mastodon host, with CORS headers. It cannot be safely changed once set either.

How do I send Mastodon email with port 25 closed?

Point Mastodon at a mail provider's submission port. Outbound port 25 is closed on every VPS and is not opened on request; send mail through a mail provider on port 465 or 587. Mastodon defaults SMTP_PORT to 25, so an instance left on the default cannot send confirmation or password-reset mail, and new users never finish signing up.

Give the provider's details to the setup wizard, or edit .env.production afterwards and restart mastodon-web and mastodon-sidekiq. On 587, the default SMTP_ENABLE_STARTTLS=auto upgrades the connection with STARTTLS. On 465, add SMTP_SSL=true, which switches Mastodon to SMTP over TLS.

SMTP_SERVER=smtp.your-provider.example
SMTP_PORT=587
[email protected]
SMTP_PASSWORD=app-password-from-the-provider
SMTP_FROM_ADDRESS="Mastodon <[email protected]>"
# port 465 instead: SMTP_PORT=465 and SMTP_SSL=true

Where does the disk go, and how do I keep it in check?

Into the cache of remote media. Every post from another server that reaches your timelines brings its images and videos with it. tootctl cleans the cache: media remove deletes cached attachments from other servers older than 7 days by default, and preview_cards remove deletes link-preview thumbnails older than 180 days by default, with a warning against going under 14. Run both from a timer and check media usage once a week.

Uploads can also go to S3-compatible object storage instead of the VPS disk. Mastodon's backup guide then leaves those files to the storage provider.

cd /home/mastodon/live
RAILS_ENV=production bin/tootctl media usage
RAILS_ENV=production bin/tootctl media remove --days 7
RAILS_ENV=production bin/tootctl preview_cards remove --days 30

What do I back up?

The four items of Mastodon's backup guide, copied off the VPS. No plan includes backups, so keep your own copy of anything that matters.

• PostgreSQL, with pg_dump: accounts, posts and follows, the data that matters most.
• .env.production: the application secrets. Lose them and users are logged out, two-factor authentication stops working and Web Push subscriptions break.
• public/system: uploaded files, when they live on the VPS disk.
• /var/lib/redis/dump.rdb: the only Redis file the guide asks for.

A backup that stays on the same disk does not survive the loss of the server. The same four items are what you carry when you move to another VPS.

Which plan fits a Mastodon instance?

Mastodon's documentation sets no minimum for RAM or disk. The rows below come from the five services it runs and from the media cache, not from load tests. The vCPU of every plan are shared: they are scheduled on physical cores that neighbouring VPS also use. The RAM and NVMe space of your plan are reserved for your VPS only. Byte is left out: 1 vCPU / 2 GB / 40 GB is better spent on a WireGuard endpoint or a small website.