Debian/Ubuntu Packages

To allow the system to check the packages authenticity, you need to provide the release key.

# Add the release PGP keys:
sudo mkdir -p /etc/apt/keyrings
sudo curl -L -o /etc/apt/keyrings/syncthing-archive-keyring.gpg https://syncthing.net/release-key.gpg

The stable channel is updated with stable release builds, usually every first Tuesday of the month.

# Add the "stable" channel to your APT sources:
echo "deb [signed-by=/etc/apt/keyrings/syncthing-archive-keyring.gpg] https://apt.syncthing.net/ syncthing stable" | sudo tee /etc/apt/sources.list.d/syncthing.list

The candidate channel is updated with release candidate builds, usually every second Tuesday of the month. These predate the corresponding stable builds by about three weeks.

# Add the "candidate" channel to your APT sources:
echo "deb [signed-by=/etc/apt/keyrings/syncthing-archive-keyring.gpg] https://apt.syncthing.net/ syncthing candidate" | sudo tee /etc/apt/sources.list.d/syncthing.list

And finally.

# Update and install syncthing:
sudo apt-get update
sudo apt-get install syncthing

Distribution Package Preferred Over This Version

To make sure the system packages do not take preference over those in this repository, you need to adjust the priority/preference.

# Increase preference of Syncthing's packages ("pinning")
printf "Package: *\nPin: origin apt.syncthing.net\nPin-Priority: 990\n" | sudo tee /etc/apt/preferences.d/syncthing.pref

HTTPS Method Driver Missing

Depending on your distribution, you may see an error similar to the following when running apt-get:

E: The method driver /usr/lib/apt/methods/https could not be found.
N: Is the package apt-transport-https installed?
E: Failed to fetch https://apt.syncthing.net/dists/syncthing/InRelease

If so, please install the apt-transport-https package and try again:

sudo apt-get install apt-transport-https

Server Certificate Verification Failed

Especially for older distributions, your system TLS certificate store might be outdated. Since October 2021, a newer Let's Encrypt root certificate must be installed, or you may see an error similar to the following when running apt-get:

E: Failed to fetch https://apt.syncthing.net/dists/syncthing/stable/binary-armhf/Packages
server certificate verification failed. CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none
E: Some index files failed to download. They have been ignored, or old ones used instead.

Please make sure you have the latest version of the ca-certificates package and try again:

sudo apt-get update
sudo apt-get install ca-certificates