Release Channels

There are two different release channels that can be selected. The stable channel is the more stable one, while candidate releases are closer to development. Candidate releases get promoted to stable after a certain period of testing.

There are a few trade-offs between the two:




More Stable

More Experimental

Features & Fixes

One month behind


Auto Upgrades


Mandatory 1

Anon. Usage Reporting




Fully supported

Fully supported 2

Run the candidate channel if you are technically savvy and enjoy new features. Run the stable channel if you want to minimize the amount of surprises you might run into.


Auto upgrades are not enabled in builds delivered via APT or Snap.


Yes, there is intentionally no difference here.


Barring blocking issues, stable versions are released on the first Tuesday of the month. A new candidate releases is made on the second Tuesday of the month.

How to Choose

Built-in / GitHub

For releases obtained from or GitHub, with built-in upgrade functionality, the choice is made in the “Settings” dialog. Set the “Automatic upgrade” drop down to either “Stable releases only” or “Stable releases and release candidates”.

APT (Debian)

The choice between stable and candidate is done in the APT source configuration. Please see our APT instructions.


The snap tool can be told to install the candidate channel, but defaults to the stable channel. See the Snap documentation for detail.

Some Other Distribution Channel

If you are getting packages from your Linux distribution, NAS vendor, etc., then you should be getting the stable channel. If you get a release candidate you should complain to your distributor or vendor and refer them to this page.


What’s the relationship between candidate and release exactly?

Every new feature and bugfix begins its life in the development branch, master. Once a month the current master becomes a release candidate. This version is identified by “-rc” in it’s name, for example v1.5.0-rc.1.

Those running the candidate channel will update to this release candidate. For the next three weeks it is tested “in the wild”. Any new, serious issues that are discovered are fixed, and new release candidates v1.5.0-rc.2 etc are created as needed. These release candidates do not include any new features or non-essential bugfixes added to master in the meantime.

Stable releases are given version numbers without any suffix - v1.5.0. Unless any serious issues were discovered, this release is exactly identical to the “-rc.1” release candidate three weeks prior.

The cycle then restarts one week later with a new release candidate based on the current master branch.

Which bugfixes trigger a new release candidate?

Those that fix a regression since the last release. Lets say the current release is v1.5.0. We release v1.5.1-rc.1 and discover a new problem that is not present in v1.5.0. This gets fixed and we release a new v1.5.1-rc.2 candidate. However, if we discover and fix a problem that’s been present since v1.4.0, this fix will instead be incorporated in the next regular cycle.

What’s the difference between the latest candidate and the following stable release?

Nothing. If we release v1.5.1-rc.1 and no serious problems are discovered during the next twelve days, this is the exact software that will become v1.5.1 for general consumption. Since the version number is different it requires a rebuild and the release signatures / hashes are different. If you are on the candidate channel, your Syncthing will “upgrade” from v1.5.1-rc.1 to v1.5.1 when we make the release. This is normal.