Privacy

Swarm is a BitTorrent client, so it talks to other computers whenever it downloads or shares, the way every BitTorrent client does. Apart from that it goes on the network by itself for two things only: anonymous counts of how many copies are installed and in use, which you can turn off, and looking for updates.

BitTorrent itself

While a torrent is downloading or seeding, the computers sharing it (peers) and the trackers it lists see your network address, which torrent you're sharing and which pieces you have. That is how BitTorrent works, and it's true of every client. Swarm also finds peers through the DHT, peer exchange and, on your own network, local peer discovery, and it asks your router to open its port (UPnP / NAT-PMP). Each of these can be switched off in Settings, and encryption can be required. Swarm sends nothing about you to peers or trackers beyond what the protocol needs: its name and version as the client's name, and a random peer id.

Only download and share what you have the right to. Swarm's built-in search and its starting suggestions cover free and legal sources only.

Usage counts

Swarm sends a short message to stats.syncster.dev, a service we run:

• When it's installed or updated: once, the first time it runs on a computer, and once more the first time it runs as a new version.
• When it's used: at most once a day, on a day you use it.

Each message carries:

The id is random digits made the first time Swarm runs. Nothing about you or your computer goes into it: it only tells one copy of Swarm from another, so each is counted once. A value Swarm can't find out is left out. The service works out the country from the network address a message comes from, and stores the country only. The address itself is never stored.

Turning them off

Untick Help ▸ Send Anonymous Usage Statistics and no more usage messages are sent. They're also never sent when the environment variable SWARM_NO_STATS=1 or DO_NOT_TRACK=1 is set.

Updates

Swarm looks for a new version as it starts (at most once an hour) and every six hours while it's open. It reads one small file, https://storage.googleapis.com/swarm-releases/updates/latest.json, which says what the newest version is; nothing about you or your computer is sent with it. When a newer version is out, Swarm downloads it from the same place, checks it against the checksum in that file, and installs it when you quit (on macOS, only an app signed by Swarm's developer is ever put in). Help ▸ Check for Updates Automatically and Help ▸ Install Updates Automatically turn this off.

What is never sent to us

• Which torrents you have, their names, or anything you download or share
• File names, folder names or paths
• Your name, email address, user name or computer name
• What you do in Swarm: no tracking of commands or clicks, no crash reports

Swarm has no accounts and shows no ads, and nothing is sold or shared.

When you ask

• Search sends what you type to the sources you have ticked (for example the Internet Archive or Academic Torrents), and to a Torznab source you added yourself, with its key.
• RSS feeds you add are read from their sites every so often.
• Adding a torrent by its web address downloads the .torrent file from that site.
• The web remote, when you turn it on, listens on your network for your browser, behind the user name and password you set.
• Help ▸ Swarm Website and the syncster.dev link in About Swarm open those sites in your web browser.

On your computer

Swarm keeps a few small files in its data folder: its settings (settings.json, client.json, frame.json), your torrents and how far each has got (state.bin), feeds, rules, search sources, categories, tags and the schedule (extras.json), the updater's switches (updates.json) and the usage-statistics id, last reported version and switch (stats.json). What you download goes in the folders you choose.

This website

Pressing a download button tells the same statistics service that Swarm was downloaded: the product, the version and the system it's for (macOS or Windows). Nothing about you is in it. The website sets no cookies and runs no ads or trackers. Besides that service, which the home page also asks for the number of installs to show it, it loads nothing from other sites. It's hosted on Netlify, and downloads are served from Google Cloud Storage (storage.googleapis.com).

Questions: syncster.dev. Last changed 7 November 2026.