Port 1935: RTMP
Port 1935 is RTMP, the Real-Time Messaging Protocol originally built for Flash media streaming. It is still the standard port for pushing a live stream from broadcasting software into services like YouTube and Twitch before they transcode it for viewers.
| Port number | 1935 |
|---|---|
| Service | Real-Time Messaging Protocol |
| Protocol | TCP |
| Category | VoIP & streaming |
| Default encryption | No |
How do I check whether port 1935 is open?
Port 1935 carries TCP, so a connection either completes its handshake or it does not, which makes the check definitive.
| Question | Command | What to know |
|---|---|---|
| Is it open on a remote host? | nc -vz example.com 1935 | A TCP handshake either completes or it does not, so netcat gives a definitive answer in one line. |
| Same check on Windows | Test-NetConnection example.com -Port 1935 | Built 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 ':1935 ' | Lists the process bound to port 1935 on Linux. On macOS use lsof -nP -iTCP:1935 -sTCP:LISTEN, on Windows netstat -ano | findstr :1935 |
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 1935 used for?
Port 1935 is RTMP, the Real-Time Messaging Protocol originally built for Flash media streaming. It is still the standard port for pushing a live stream from broadcasting software into services like YouTube and Twitch before they transcode it for viewers.
Is port 1935 TCP or UDP?
Port 1935 (RTMP) uses TCP.
Is port 1935 secure?
Port 1935 is not encrypted by default. Where possible, use an encrypted alternative or tunnel it over TLS or a VPN.
Should I open port 1935 on my firewall?
Only if you specifically need RTMP. Expose it to the smallest set of trusted sources, and never open database or Windows-service ports to the whole internet.