Port 8384: Syncthing

Port 8384 is the default web interface for Syncthing, an open-source tool that synchronizes files directly between devices without a central cloud server. It is meant to be reached only from the local machine or network, not the open internet.

TCPFile transferUnencrypted by default
Port number8384
ServiceSyncthing web GUI
ProtocolTCP
CategoryFile transfer
Default encryptionNo
Security note. Port 8384 is not encrypted by default. Restrict it to trusted networks, or use an encrypted alternative where one exists, to avoid exposing credentials and data in transit.

How do I check whether port 8384 is open?

Port 8384 carries TCP, so a connection either completes its handshake or it does not, which makes the check definitive.

QuestionCommandWhat to know
Is it open on a remote host?nc -vz example.com 8384A TCP handshake either completes or it does not, so netcat gives a definitive answer in one line.
Same check on WindowsTest-NetConnection example.com -Port 8384Built into PowerShell. TcpTestSucceeded in the output is the answer; telnet is not installed by default on modern Windows.
What is listening locally?ss -tlnp | grep ':8384 'Lists the process bound to port 8384 on Linux. On macOS use lsof -nP -iTCP:8384 -sTCP:LISTEN, on Windows netstat -ano | findstr :8384

Replace example.com with the host you are testing. A blocked port and a port with nothing listening on it look identical from the outside, so if a service should be running, check locally before blaming the firewall.

Frequently asked questions

What is port 8384 used for?

Port 8384 is the default web interface for Syncthing, an open-source tool that synchronizes files directly between devices without a central cloud server. It is meant to be reached only from the local machine or network, not the open internet.

Is port 8384 TCP or UDP?

Port 8384 (Syncthing) uses TCP.

Is port 8384 secure?

Port 8384 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.

Should I open port 8384 on my firewall?

Only if you specifically need Syncthing. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.