Syncthing-Fork

Last reviewed Sep 13, 2026 · 865 words

Since the official Syncthing Android app was discontinued at the end of 2024, Syncthing-Fork is the Android client. It is not a server, not a service, and not a Syncthing replacement: it wraps the standard Syncthing engine in an Android app whose extra job is keeping your phone's battery alive. Install it from F-Droid or the GitHub releases, pair it with the Syncthing instance you already run, and the phone becomes one more device in the mesh, with your camera roll landing on the server within a minute of taking a photo.

What the fork adds to stock Syncthing

The engine inside is unmodified Syncthing, so protocol, encryption and folder semantics are identical to the desktop and server builds. The fork's value is everything around it: run conditions, so sync only happens on Wi-Fi, on named SSIDs, while charging, or above a battery threshold; per-folder and per-device versions of those conditions; a proper Android UI for folder and device management instead of the web GUI squeezed into a WebView; and quality-of-life items such as an SD card guide, a built-in log viewer and a status notification that tells the truth. The maintainer, Catfriend1, has kept the fork current with Syncthing releases since 2017, which is the "actively maintained" line in the catalogue and the reason it outlived the official app.

Install and pair in five minutes

Add the F-Droid repository or download the APK from the releases page, grant the storage and battery-optimisation exemptions the setup wizard asks for, and open Devices. Add your server by scanning its device ID QR code from the server's web GUI on port 8384, then accept the phone on the server side. Share a folder from either end; the other side gets a prompt to accept and pick a local path.

The pattern that most people want is a one-way camera upload:

The phone shares DCIM/Camera as Send Only. The server accepts it as Receive Only into a directory that your photo tool watches. Deleting a photo on the phone then does nothing on the server, and nothing the server does can touch the phone. Pair that with Immich or a plain directory and you have Google Photos upload without Google, which is why this app shows up on the Google Drive alternatives lists.

Run conditions are the feature

Set them per folder. Camera upload: any Wi-Fi, any battery. A large media folder you pull to the phone: home SSID only, charging only. Documents you edit on the phone: always. The result is a phone that syncs everything you care about without draining 15 percent overnight, which stock Syncthing on Android could never quite promise. Two more toggles matter: "sync only when charging" as a global fallback for a phone with a tired battery, and the option to stop Syncthing entirely when conditions are not met rather than leaving it idling, which saves noticeably more.

Android storage is where setup gets fiddly

The catalogue's "initial setup can be fiddly" con is Android's fault more than the app's. Three things bite. Android 11 and later require the "All files access" permission for anything outside the app's own directory; the wizard asks for it, and if you decline, folder pickers show empty trees. External SD cards are read-only to normal apps except for an app-specific directory, so a folder on the SD card must be Receive Only or live inside Android/media/, and the in-app SD card guide explains the exact path. And battery optimisation must be disabled for the app or Android will kill the engine within minutes of the screen turning off, which shows up as "the phone only syncs when I open the app".

Add .thumbnails and .trashed-* to the camera folder's ignore patterns before the first scan, or you sync thousands of tiny files and a bin nobody wanted.

It is not a cloud, and it needs a peer that is always on

Syncthing has no server, so two phones that are never awake at the same time never sync. The always-on peer is your home server, NAS or a small VPS running the normal Syncthing build; the phone talks to that. If you want a web interface, sharing links, and calendar and contacts in the same place, that is Nextcloud, and the Nextcloud vs Syncthing comparison is the read for deciding which model you actually want. The file sync category has the rest.

What I'd do

Install Syncthing-Fork from F-Droid, disable battery optimisation when asked, pair it with the home server, and set up exactly one folder first: DCIM/Camera as Send Only to a Receive Only folder on the server, with the ignore patterns above. Leave it for a week and check the server. Then add a documents folder with "always" conditions and a music folder with "home Wi-Fi plus charging". That is a phone backup and a phone sync in one app, with no account anywhere.