Syncthing

"Open Source Continuous File Synchronization" — peer-to-peer file sync between your own machines, with no account and no server to rent. Go, MPL-2.0, 88,364★ / 5,455 forks / 381 open issues, repository created 2013-11-26, latest release v2.1.3 (2026-08-05), pushed 2026-09-07. By a wide margin the largest project this spoke holds, and the oldest.

Already present in the corpus before it had a page: self-host-user-survey-2025 put it second in the Files category with 1,058 selections, behind Nextcloud's 1,236.

The README sells goals, not freedom from anything

The README is 470 words and almost all of it is a ranked goal list — safe from data loss, secure against attackers, easy to use, automatic, universally available, for individuals, everything else — stated "in order of importance, the most important ones first." Data integrity outranks security; security outranks usability; the individual user is named as the constituency at position six.

That is a different genre from every other source here. hometube, pocketpal-ai and locally-uncensored lead with what they refuse — no cloud, no telemetry, nothing leaves the device. Syncthing's README makes no privacy claim at all and never uses the word cloud. A project can be the strongest instance of this spoke's subject and decline to market itself as one.

Applying this spoke's own test

self-hosting's test is name the resource the software needs that you do not own. Syncthing has an answer, and unusually, the answer is written down by the project rather than found by us.

The front page makes the strong claim: "Your data is your data alone and you deserve to choose where it is stored" and "None of your data is ever stored anywhere else other than on your computers. There is no central server that might be compromised."

The documentation names the infrastructure anyway. Two services stand between two devices that cannot reach each other directly:

Global discovery — "Given a device ID it's possible to find the IP address for that device, if global discovery is enabled on it" (FAQ). Device ID resolves to current IP.
Relays — "Relay servers are run by volunteers all over the world" and "Relays do not and can not see the data transmitted via them" (FAQ). The relaying documentation is more precise, and more useful: relaying is "enabled by default but will only be used if two devices are unable to communicate directly with each other"; the connection stays end-to-end encrypted and the relay "only retransmits the encrypted data much like a router"; but "a device must register with a relay in order to be reachable over that relay, so the relay knows your IP and device ID," and "the relay operator can see the amount of traffic flowing between devices."

So the honest statement is narrower than the front page's and the project's own docs make it: the data has no third party; the connectivity does. Content is unreadable to a relay, and IP, device ID and traffic volume are not. That is metadata held by a volunteer whose identity the user did not choose, by default, whenever NAT gets in the way.

Where that lands in this spoke's argument

The founding finding here is relocation sold as removal: self-hosting moves a dependency rather than deleting one, and the marketing describes the move as a deletion. Syncthing is the case that comes closest to actual removal — there is no server to rent, no host to administer, no account — and it is still not zero. What it removes is the storage dependency; what remains is a rendezvous dependency, which is a smaller and differently-shaped thing.

And the disclosure pattern is the opposite of hometube's, which claimed no cloud dependencies with the cookie requirement several paragraphs down. Here the loose sentence is on the marketing page and the precise one is in the manual, in more detail than a user would ask for. Nothing is hidden; the summary is just looser than the documentation, which is the ordinary failure and worth distinguishing from the deliberate one.

Funding, and the posture this spoke keeps looking for

The site names Kastelo Inc., which "provides commercial support for Syncthing and sponsors Syncthing with development resources," plus Möbius Sync (iOS) and REEF Solutions. So the answer to "who is paid to notice when it breaks" is: a company sells support around it, and the project stays MPL-2.0 and community-run. That is a third funding shape beside ever-gauzy's nobody and the store-mediated apps here.

Not verified

The star count, release tag and survey numbers are dated snapshots (2026-09-07). Nothing here audits the encryption claims, the relay behaviour, or whether global discovery can be turned off — the FAQ passage read for this page does not say, and the configuration reference was not opened. No performance or reliability figure of any kind was sought.

self-hosting · self-host-user-survey-2025 · hometube · pocketpal-ai · ever-gauzy · kastelo · foss-application · open-source-alternative · synthesis