syncthing.exe

Syncthing File Synchronization Daemon

Application ProcessSafeFile Synchronization

CPU Usage

1-12%

Memory

40-180 MB

Location

C:\Program Files\Syncthing

Publisher

The Syncthing Project

Quick Answer

syncthing.exe is safe. It’s the official Syncthing daemon that synchronizes folders directly between devices using encrypted peer-to-peer connections.

Is it a Virus?

✔ NO - Safe

Must be in C:\Program Files\Syncthing\syncthing.exe

Warning

Many processes normal

Each shared folder may run its own worker; ensure legitimate syncthing.exe path

Can I Disable?

✔ YES

To stop syncing, exit the GUI or stop the service

What is syncthing.exe?

syncthing.exe is the executable for the Syncthing file synchronization daemon. It runs as a background service that coordinates direct, encrypted sync between devices. It monitors configured folders and transfers data peer-to-peer without central servers, enabling private file syncing.

Syncthing uses a peer-to-peer architecture with TLS-based connections and device IDs. It runs as a daemon, manages folders via a config file, negotiates sync with trusted devices, and uses NAT traversal to connect devices on LAN or over the internet.

Quick Fact: Syncthing pioneered peer-to-peer, encrypted folder synchronization, removing the need for central servers while preserving privacy and data control.

Types of Syncthing Processes

GUI Process: Web-based GUI for managing folders and devices
Daemon Process: Core synchronization engine running in background
Service Process: Windows service equivalent for auto-start and background operation

Is syncthing.exe Safe?

Yes, syncthing.exe is safe when it's the legitimate file from The Syncthing Project downloaded from official sources.

Is syncthing.exe a Virus or Malware?

The real syncthing.exe is NOT a virus. However, malware can masquerade with similar names. Always verify location and signature.

How to Tell if syncthing.exe is Legitimate or Malware

File Location:: Must be in C:\Program Files\Syncthing\syncthing.exe or C:\Program Files (x86)\Syncthing\syncthing.exe. Any other location is suspicious.
Digital Signature:: Right-click syncthing.exe → Properties → Digital Signatures → should show a signer like "The Syncthing Project".
Resource Usage:: Normal usage is 1-12% CPU per process, 40-180 MB memory. Extremely high usage when idle is suspicious.
Behavior:: Syncthing should run as a daemon or service and only when you start it or configure automatic startup. Unexpected background activity warrants a scan.

Red Flags: If syncthing.exe is located in unusual folders (like Temp, AppData\Roaming, or System32), runs when the system is idle, has no digital signature, or uses constant high network activity, scan your system with antivirus software. Be wary of similarly named files like "syncthing64.exe" from untrusted sources.

Why Is syncthing.exe Running on My PC?

syncthing.exe runs to keep folders synchronized across devices. It can operate as a background daemon or service, ensuring local and remote folders stay in sync without manual transfers.

Reasons it's running:

Active Folder Sync: You have one or more folders configured to sync with one or more devices; the daemon runs to manage transfers.
Background Synchronization: Syncthing is configured to run in the background so changes propagate even when the GUI isn't open.
New Device Discovery: New devices or peers are available and pairing is in progress, initiating connections.
Startup Behavior: The service or GUI is set to launch on system startup or user login for seamless syncing.
Folder Status Checks: Regular checks confirm folder integrity and detect changes across devices, triggering transfers as needed.

Can I Disable or Remove syncthing.exe?

Yes, you can disable syncthing.exe. You can stop syncing, disable startup, or uninstall Syncthing if you no longer need it.

How to Stop syncthing.exe

Pause or Stop via GUI: Open the Syncthing GUI and click the Stop or Pause button to halt synchronization.
Stop Windows Service: Open Services (services.msc), locate Syncthing Service, and click Stop.
End Process: Open Task Manager, find syncthing.exe, and End Task.
Prevent Startup: Task Manager → Startup tab → Disable Syncthing. This stops automatic startup.
Stop Background Activity: In GUI settings, disable "Start in background" or equivalent to prevent background syncing.

How to Uninstall Syncthing

✔ Windows Settings → Apps → Apps & Features → Syncthing → Uninstall
✔ Control Panel → Programs → Uninstall a program → Syncthing → Uninstall
✔ Delete Syncthing configuration folders if you want a clean removal: typically at C:\Users\<YourUser>\AppData\Local\Syncthing

Common Problems: High CPU or Memory Usage

If syncthing.exe is consuming excessive resources:

Common Causes & Solutions

Too Many Active Folders: Limit the number of configured folders or exclude large directories not needed for sync.
Active Large File Transfers: Pause or stagger transfers for large files; schedule intensive sync tasks during off-peak times.
Frequent Device Discoveries: Disable unnecessary device discovery in settings if devices are known and trusted.
Outdated Version: Update to the latest Syncthing release to benefit from performance improvements.
Antivirus or Firewall Interference: Ensure Syncthing has network access and is not being sandboxed; whitelist the executable.
Background Service Running Indefinitely: If not needed, disable startup and stop the service to free resources.

Quick Fixes:
1. Quick Fixes:
2. 1. Open Syncthing GUI and identify folders with heavy activity
3. Pause or selectively exclude large folders
4. Update to the latest Syncthing version
5. Whitelist Syncthing in your antivirus/firewall
6. Disable Start in background and startup entries

Frequently Asked Questions

Is syncthing.exe a virus?

No, the legitimate syncthing.exe from The Syncthing Project is not a virus. Verify the file is located at C:\Program Files\Syncthing\syncthing.exe and has a valid digital signature from The Syncthing Project.

Why is syncthing.exe using so much CPU?

High CPU can occur during large or many simultaneous sync operations, especially when scanning new folders or syncing large files. Check active transfers in the GUI and pause or stagger workloads.

Can I delete syncthing.exe?

Yes, you can uninstall Syncthing via Settings → Apps or Control Panel. Your synced data is stored in configured folders and remains unless you delete the folders themselves.

Can I disable syncthing.exe?

Yes, you can stop the daemon or service, disable startup, and prevent background syncing. This will stop automatic synchronization until you re-enable it.

Why does Syncthing start on boot?

If configured, Syncthing can start on system boot to keep folders in sync without manual intervention. Disable startup in Task Manager or Services to stop this behavior.

How do I reduce Syncthing's resource usage?

Limit the number of folders, pause heavy transfers, update to the latest version, and enable scheduling or dark mode features that reduce background activity.