moonlight.exe

Moonlight Game Streaming Client

Application ProcessSafeGaming/Streaming

CPU Usage

2-12%

Memory

120-420 MB

Location

Program Files

Publisher

Moonlight Team

Quick Answer

moonlight.exe is safe. It's the Moonlight Game Streaming Client used to receive game streams from a host PC. It runs content in lightweight processes to minimize latency and preserve responsiveness.

Is it a Virus?

✔ NO - Safe

Must be located in C:\Program Files\Moonlight\moonlight.exe or C:\Program Files (x86)\Moonlight\moonlight.exe

Warning

Many Moonlight processes normal

Multiple instances may run for streaming sessions and controller input handling

Can I Disable?

✔ YES

End streaming sessions or disable startup to stop moonlight.exe from running

What is moonlight.exe?

moonlight.exe is the Windows executable for the Moonlight Game Streaming Client. It connects to a host PC to stream games, captures user input, and renders video and audio on the client device. It supports local and remote GameStream sessions for flexible play.

Moonlight employs a streaming pipeline that negotiates a GameStream session, handles input mapping, and delivers encoded video and decoded audio with low latency. It runs as modular processes to isolate streaming work from UI tasks.

Quick Fact: Moonlight is an open-source implementation of NVIDIA GameStream, enabling cross-device streaming with client-server coordination.

Types of Moonlight Processes

Launcher Process: Initial startup and session negotiation (1 instance)
Streaming Renderer: Video decoding and display for the client screen (multiple instances)
Input Handler: Captures keyboard/controller input and forwards to host
Networking Module: Manages GameStream transport and protocol packets
Auxiliary Service: Background tasks like connection keep-alive or telemetry
Helper/Launcher: Assist with codec selection and session resumption

Is moonlight.exe Safe?

Yes, moonlight.exe is safe when it’s the legitimate Moonlight client from a trusted source (official Moonlight project repository or Moonlight-hosted distributions).

Is moonlight.exe a Virus or Malware?

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

How to Tell if moonlight.exe is Legitimate or Malware

File Location: Must be in C:\Program Files\Moonlight\moonlight.exe or C:\Program Files (x86)\Moonlight\moonlight.exe. Any moonlight.exe elsewhere is suspicious.
Digital Signature: Right-click moonlight.exe in Explorer → Properties → Digital Signatures. Should display a signer such as "Moonlight Team" or official project signatories.
Resource Usage: Normal usage is 2-12% CPU per streaming session, 120-420 MB total memory. Constantly high usage with no host connection is suspicious.
Behavior: Moonlight should only run during an active streaming session or when a host is available. Background persistence without a host is a red flag.

Red Flags: If moonlight.exe is located in unusual folders (Temp, AppData), runs without an active host, has no valid signature, or uses resources constantly, scan with antivirus and confirm the source of the executable.

Why Is moonlight.exe Running on My PC?

Moonlight launches to establish and maintain a streaming session with a host PC, handle input routing, and render the streamed game on the client device. It may run during active play or when a host is discovered.

Reasons it's running:

Active Game Streaming: A host is connected and a game is being streamed; moonlight.exe runs to manage the session and codecs.
Background Session Discovery: Moonlight may scan for previously paired hosts or await a new GameStream host in the network.
Startup Program: Moonlight is configured to start with Windows or a user login, preparing for quick streaming.
Input and Control Handling: Dedicated processes manage input from keyboard, mouse, or game controllers during streaming.
Network Reconnection: If the host is temporarily unreachable, moonlight.exe may stay active to re-establish the session when possible.

Can I Disable or Remove moonlight.exe?

Yes, you can disable moonlight.exe. You can stop streaming sessions, disable startup, or uninstall Moonlight if you no longer need it.

How to Stop moonlight.exe

End Streaming Session: In Moonlight, disconnect from the host or close the client window to stop the process.
Close Client: Exit Moonlight from the system tray or UI to terminate the streaming client.
End All Moonlight Processes: Open Task Manager (Ctrl+Shift+Esc), locate moonlight.exe, right-click → End Task.
Prevent Startup: Task Manager → Startup tab → Disable Moonlight
Disable Background Streaming: In Moonlight settings, disable automatic reconnection or background streaming.

How to Uninstall Moonlight

✔ Windows Settings → Apps → Apps & Features → Moonlight → Uninstall
✔ Control Panel → Programs → Uninstall a program → Moonlight → Uninstall
✔ Consider alternative streaming clients if you need different features

Common Problems: Latency, Stuttering, or Connection Drops

If moonlight.exe is not delivering smooth streaming or disconnects frequently:

Common Causes & Solutions

Weak network bandwidth: Ensure both host and client have stable, high-speed connections; use wired Ethernet where possible.
High CPU/GPU load on host: Close unnecessary apps on the host, enable hardware encoding, or adjust quality settings.
Inadequate UDP/TCP ports: Forward necessary ports or enable UPnP on the network; ensure firewall allows Moonlight traffic.
Incorrect codecs or resolution: Match client and host codec profiles and reduce resolution/bitrate to stabilize streams.
Background apps consuming bandwidth: Pause updates, cloud backups, and other bandwidth-heavy tasks during a session.
Outdated Moonlight version: Update Moonlight to the latest release from the official source.

Quick Fixes:
1. Verify host is reachable and stream from a wired connection
2. Lower resolution and bitrate in Moonlight settings
3. Restart Moonlight and the host machine if needed
4. Check firewall rules for Moonlight traffic
5. Update both Moonlight client and host persistence components

Frequently Asked Questions

Is moonlight.exe a virus?

No, the legitimate moonlight.exe from the Moonlight project is not a virus. Ensure the file is located at C:\Program Files\Moonlight\moonlight.exe or C:\Program Files (x86)\Moonlight\moonlight.exe and verify a trusted signature from the Moonlight Team.

Why is moonlight.exe using so much CPU?

High CPU can occur if decoding or upscaling occurs on a weak device, or if the host is busy. Check host load, reduce stream quality, and ensure hardware acceleration is enabled where available.

Can I delete moonlight.exe?

Yes, you can uninstall Moonlight through Windows Settings → Apps if you no longer need the client. You may lose access to streaming unless you reinstall later.

Can I disable moonlight.exe at startup?

Yes. Disable Moonlight in Task Manager → Startup tab, or disable any startup tasks that launch Moonlight automatically.

Why won't Moonlight connect to my host?

Verify the host is on the same network, the host PC is running Moonlight stream server, and that firewalls permit the connection. Re-pair devices if necessary.

How can I improve streaming quality?

Use a wired network, enable hardware encoding, lower resolution/bitrate, and keep drivers up to date. Avoid peak network hours and close background bandwidth-heavy apps.