What is port 49152 used for?

Port 49152 is the first port in the dynamic or ephemeral range (49152-65535). The OS hands these out automatically for outgoing connections, so they're not tied to any specific service.

Is it safe to kill a process using port 49152?

Usually there's nothing to kill. A process on an ephemeral port is just one end of a normal outgoing connection. Identify the owning app first; only act if it's something you actually want to stop.

Why do I see so many high-numbered ports in use?

That's normal. Every outbound connection your Mac makes uses an ephemeral port from this range. Seeing many of them in a monitor is expected behavior.

Port 49152: What's Using It and Is It Safe to Kill?

Port 49152 is the first port in the dynamic, or ephemeral, range that runs from 49152 to 65535. Unlike a database or web port, it isn’t tied to a particular service. The operating system assigns ports from this range automatically whenever your Mac opens an outgoing connection.

What typically uses port 49152

Outgoing connections: Apps that connect out (browsers, sync clients, anything talking to a server) get a temporary local port from this range.
Temporary listeners: Some software opens a short-lived listener on a dynamic port for peer-to-peer transfers or local IPC.

Because assignment is automatic, the exact port varies from one connection to the next. Seeing 49152, or any high number, in use is part of normal networking. For more on the ranges, see Common ports and what they’re used for.

Is it safe to kill?

There’s usually nothing to kill in the sense of a stuck server. A process using 49152 is typically just one side of a normal connection. Identify the owning app first, and only stop it if it’s an application you actually want to quit. Ending a connection’s port on its own doesn’t accomplish anything useful.

Is it suspicious?

Generally no. Heavy use of the ephemeral range is exactly what you’d expect from an active machine. It’s only worth a closer look if a specific unfamiliar process is making connections you can’t explain, in which case the app, not the port number, is what to investigate.

How to find what’s on port 49152 on macOS

lsof -i :49152

More usefully, look at what your apps are actually connecting to:

lsof -i -P | grep ESTABLISHED

Portie shows ephemeral ports alongside the apps that own them in its live view, so you can see which application a high-numbered connection belongs to instead of guessing.