Nearby devices

What is screensharingd?

screensharingd listens for Screen Sharing and VNC connections. When someone views or controls this Mac from another computer, the screen goes out through screensharingd.

Process: screensharingdMade by AppleApplies to: macOS 14 Sonoma and later. Checked on macOS 27.2.Checked: 1 November 2026

Short answer

Part of macOS. It accepts Screen Sharing and VNC connections from other computers, so another person can see and control this Mac.

Safe to block

Safe to block if nobody needs to reach this Mac remotely. It's better to turn off Screen Sharing in Sharing settings.

Path: /System/Library/CoreServices/RemoteManagement/screensharingd.bundle/Contents/MacOS/screensharingd
launchd label: com.apple.screensharing
Signing identifier: com.apple.screensharing.daemon

What it is

The man page says that screensharingd “listens for VNC connections from clients”. It should not be run directly. To use it, turn on Screen Sharing or Remote Management.

The program is inside /System/Library/CoreServices/RemoteManagement. launchd starts it for the system as com.apple.screensharing.

Apple lists TCP and UDP port 5900 for Screen Sharing and Apple Remote Desktop. Kerberos on port 88 is listed for Screen Sharing authentication.

Why it uses the network

A screen sharing session. While someone views this Mac, it sends the screen to them and receives their keyboard and mouse input.
Waiting for connections. With Screen Sharing on, it listens for other computers on your network. Waiting uses almost no data.

How much is normal

With no session open, its traffic is small or none.

During a session, it can use a lot of data. A busy, high-resolution screen sends more than a still one.

If you didn't turn on Screen Sharing or Remote Management, a management profile from your organization may have. Ask your administrator.

When it uses a lot, and why

A long session. Every minute that someone watches or controls the Mac, the screen streams to them.
Video or animation on screen. A screen that changes a lot, such as a playing video, sends more than a document.
Several viewers. Each computer connected to the Mac gets its own stream.

Is it safe to block?

Safe to block

Safe to block if nobody needs to reach this Mac remotely. It's better to turn off Screen Sharing in Sharing settings.

What breaks if you block it

Other computers can't view or control this Mac with Screen Sharing or a VNC app.
Apple Remote Desktop management of this Mac stops, if your organization uses it.

Blocking means a firewall rule that refuses its connections. Don’t quit or disable a macOS process to save data: macOS starts it again, and other features depend on it.

Reduce its use

Choose Apple menu › System Settings › General › Sharing.
Turn off Screen Sharing if you don't use it. Apple says that other computers on your network then can't connect.
If you need it, use the Info button next to Screen Sharing. Allow access only for the users who need it.
Don't quit screensharingd during a session you want to keep. The session ends.

See how much it uses

Open Activity Monitor from Applications › Utilities. Click Network, then search for screensharingd.
In Terminal, list who is connected now. A connection to port 5900 is a viewer.
```
sudo lsof -nP -i :5900
```
Needs an administrator password.

With Kilobat

Kilobat writes a report after remote desktop sessions, with lags and their likely causes.
In Connections, click ⓘ on one of its rows. The popover shows this answer without going online.
Ask the same question in Terminal.
```
kilobat explain screensharingd
```
Read the last remote desktop session reports.
```
kilobat remote
```

The live view and the explanations are free. History in the app needs Kilobat Pro. Blocking needs Pro and the network filter: see the network filter, Protection and the hotspot data saver.

Questions

Is someone watching my screen?

Only if Screen Sharing or Remote Management is on and a connection is open. Check the Sharing settings and the connections on port 5900.

Does Screen Sharing use internet data?

Only if the other computer is outside your local network. A session between two Macs at home stays local.

Sources

screensharingd(8), man page installed with macOS 27.2
launchd property list com.apple.screensharing, macOS 27.2
Apple Support: Turn Mac screen sharing on or off
Apple Support: TCP and UDP ports used by Apple software products

Checked on 1 November 2026.