Network Setup

Network Requirements

Scrcpy for Android requires network connectivity between the controlling device and the target device. Understanding the network architecture helps optimize performance and troubleshoot connection issues.

Local Network Configuration

For most use cases, both devices should be on the same local network.

Prerequisites

Enable ADB over Network

On the target device (the one to be controlled), enable ADB debugging over TCP/IP:

# Using USB ADB first
adb tcpip 5555

This tells the device to listen for ADB connections on port 5555.

Find Device IP Address

Get the target device’s local IP address:

Go to Settings → About Phone → Status → IP Address
Or use: adb shell ip addr show wlan0

Example: 192.168.1.100

Test Connection

From the controlling device, test the connection:

adb connect 192.168.1.100:5555
adb devices

You should see the device listed.

Network Ports Used

Scrcpy for Android uses the following ports during operation:

Port	Direction	Purpose	Configurable
5555	Client → Target	ADB connection	Yes (via ADB)
7007	Local only	Server socket on target device	No
7008	Local only	Forwarded port on client device	Defined in `Scrcpy.java:36`

Port Forwarding Flow

The connection uses ADB’s port forwarding mechanism: The forwarding is established in SendCommands.java:109:

adb -s <ip>:<port> forward tcp:7008 tcp:7007

Public Network Access Setup

To access a device over the internet or different networks, additional configuration is required.

Exposing ADB to the public internet is a security risk. Only use this in controlled environments with proper security measures.

Method 1: Router Port Forwarding

If the target device is behind a router:

Set Static IP

Configure the target device with a static IP on your local network (e.g., 192.168.1.100).

Configure Router

Log into your router’s admin panel and add a port forwarding rule:

External Port: 5555
Internal IP: 192.168.1.100
Internal Port: 5555
Protocol: TCP

Find Public IP

Determine your network’s public IP address:

curl ifconfig.me

Example: 203.0.113.50

Connect

From the client device, connect using the public IP:

203.0.113.50:5555

Method 2: VPN Tunnel

A more secure approach using a VPN:

WireGuard

Set up a WireGuard VPN server on your network. Both devices join the VPN and communicate via private IPs.Pros: Encrypted, secure, NAT traversal

Tailscale/ZeroTier

Use a mesh VPN service for easy peer-to-peer connections without manual configuration.Pros: No port forwarding needed, cross-platform

Method 3: Reverse SSH Tunnel

If you have access to a public server:

# On target device (using Termux or similar)
ssh -R 5555:localhost:5555 [email protected]

# On client device
adb connect your-server.com:5555

Firewall Configuration

Target Device Firewall

Android doesn’t typically have a firewall by default, but if using custom ROMs or security apps:

Allow ADB port 5555

Ensure TCP port 5555 is allowed for incoming connections from your local network or VPN subnet.

Allow local server socket

Port 7007 only needs to accept local connections (from the ADB daemon), not external traffic.

Client Device Firewall

The client device initiates connections, so typically no inbound rules are needed. However:

Allow outbound TCP to port 5555 on target device
Allow local binding to port 7008 (ADB forward)

Router/Network Firewall

If devices are on different subnets within the same network:

Allow TCP port 5555 between subnets
Consider using VLANs for security isolation
Implement access control lists (ACLs) if needed

Network Performance Tuning

Bandwidth Requirements

The application’s bandwidth usage depends on your configuration:

Resolution	Bitrate	Estimated Bandwidth
1080p	2 Mbps	~2-3 Mbps total
1080p	4 Mbps	~4-5 Mbps total
1440p	8 Mbps	~8-10 Mbps total

Bandwidth includes video (H.264), audio (AAC at 128kbps), and control data. The bitrate is configurable in the app UI.

Optimizing for Different Networks

Local Wi-Fi (Optimal)
Mobile Data / 4G
Public Network / VPN

Configuration:

Bitrate: 4-8 Mbps
Resolution: Native or 1080p
Delay tolerance: 50ms

Tips:

Use 5GHz Wi-Fi for better bandwidth and lower latency
Ensure both devices have strong signal strength
Disable Wi-Fi power saving on both devices

Delay Control

The application includes delay tolerance settings to handle network latency (Scrcpy.java:342-469):

Purpose: Drops frames that arrive too late to maintain sync
Configuration: Available in app settings (50ms, 100ms, 200ms, etc.)

Algorithm:

if (System.currentTimeMillis() - (lastOffset + presentationTimeStamp) < delay) {
    // Render frame
} else {
    // Drop frame
}

Higher delay tolerance = smoother playback but increased latency. Lower values = more responsive but may stutter on slow networks.

Connection Stability

The client implements automatic retry logic (Scrcpy.java:238-340):

Initial connection: 50 attempts with 100ms intervals (5 seconds total)
Handshake timeout: 10 attempts × 100ms = 1 second
Auto-reconnect: Available in headless mode

To improve stability:

Reduce packet size: Lower resolution and bitrate
Enable QoS: Configure router Quality of Service for ADB traffic
Use wired connection: If possible, connect target device via USB tethering or Ethernet adapter

Troubleshooting Network Issues

Connection Timed Out

Symptoms: “Connection Timed out” error after startingSolutions:

Verify target device IP address is correct
Check both devices are on same network (or VPN)
Ensure port 5555 is not blocked by firewall
Restart ADB on target: adb kill-server && adb tcpip 5555
Check target device has not gone to sleep (disable battery optimization)

Laggy or Stuttering Video

Symptoms: High latency, frame drops, stutteringSolutions:

Lower bitrate setting in app
Reduce resolution
Increase delay tolerance
Move closer to Wi-Fi router
Check for network congestion (other devices using bandwidth)
Use 5GHz Wi-Fi instead of 2.4GHz

Disconnects Frequently

Symptoms: Connection drops after a few minutesSolutions:

Disable battery optimization for ADB and Scrcpy app
Keep target device screen on during mirroring
Check for Wi-Fi sleep settings
Ensure stable network (weak signal causes drops)
Enable “Keep Wi-Fi on during sleep” on both devices

Cannot Connect Over Internet

Symptoms: Works on local network but not remotelySolutions:

Verify port forwarding is correctly configured
Check router firewall allows port 5555
Test using public IP (not local 192.168.x.x)
Consider using VPN instead of port forwarding
Check ISP doesn’t block incoming connections (use DMZ as test)

Security Considerations

ADB is not encrypted and has no authentication. Anyone who can connect to port 5555 has full device access.

Best Practices

Use VPN: Always use VPN for remote access instead of exposing port 5555
Disable when not in use: Turn off ADB network listening when not needed
Whitelist IPs: Use firewall rules to allow only specific client IPs
Monitor connections: Check adb devices to see what’s connected
Use authentication: Consider ADB key-based authentication (requires initial USB pairing)

Alternative: ADB Key Authentication

For enhanced security, use ADB key-based authentication:

# Generate ADB keys (done automatically on first connection)
# Keys stored in ~/.android/adbkey and adbkey.pub

# Target device will prompt to "Allow USB debugging" on first connect
# Select "Always allow from this computer"

This ensures only authorized devices can connect, even if they know the IP address.

Get Started

User Guide

Advanced

Network Requirements

Local Network Configuration

Prerequisites

Network Ports Used

Port Forwarding Flow

Public Network Access Setup

Method 1: Router Port Forwarding

Method 2: VPN Tunnel

WireGuard

Tailscale/ZeroTier

Method 3: Reverse SSH Tunnel

Firewall Configuration

Target Device Firewall

Client Device Firewall

Router/Network Firewall

Network Performance Tuning

Bandwidth Requirements

Optimizing for Different Networks

Delay Control

Connection Stability

Troubleshooting Network Issues

Security Considerations

Best Practices

Alternative: ADB Key Authentication

Build docs developers (and LLMs) love

Get Started

User Guide

Advanced

​Network Requirements

​Local Network Configuration

​Prerequisites

​Network Ports Used

​Port Forwarding Flow

​Public Network Access Setup

​Method 1: Router Port Forwarding

​Method 2: VPN Tunnel

WireGuard

Tailscale/ZeroTier

​Method 3: Reverse SSH Tunnel

​Firewall Configuration

​Target Device Firewall

​Client Device Firewall

​Router/Network Firewall

​Network Performance Tuning

​Bandwidth Requirements

​Optimizing for Different Networks

​Delay Control

​Connection Stability

​Troubleshooting Network Issues

​Security Considerations

​Best Practices

​Alternative: ADB Key Authentication

Build docs developers (and LLMs) love

Network Requirements

Local Network Configuration

Prerequisites

Network Ports Used

Port Forwarding Flow

Public Network Access Setup

Method 1: Router Port Forwarding

Method 2: VPN Tunnel

Method 3: Reverse SSH Tunnel

Firewall Configuration

Target Device Firewall

Client Device Firewall

Router/Network Firewall

Network Performance Tuning

Bandwidth Requirements

Optimizing for Different Networks

Delay Control

Connection Stability

Troubleshooting Network Issues

Security Considerations

Best Practices

Alternative: ADB Key Authentication