Skip to main content
NetPlay allows you to play GameCube and Wii games online with other Dolphin users. This guide covers setup, hosting, joining sessions, and troubleshooting.

​
What is NetPlay?

NetPlay is Dolphin’s built-in online multiplayer feature that:
  • Synchronizes emulation between multiple players
  • Supports 2-4 players (or more for some games)
  • Works with both GameCube and Wii games
  • Requires all players to use identical game versions and settings
NetPlay emulates local multiplayer, not original online services. Both players run the game in sync over the internet.

​
Requirements

​
System Requirements

  • Stable internet: Low latency connection (< 50ms ping preferred)
  • Matching Dolphin version: All players must use the same Dolphin version
  • Same game version: Identical ISO/ROM (same region and revision)
  • Sufficient CPU: Host needs good single-core performance
NetPlay requires all players to have identical game files. Different game versions, even by a single byte, will cause desyncs.

​
Network Setup

For hosting:
  • Open port: Default port 2626 must be accessible
  • UPnP support: Automatic port forwarding (if router supports)
  • Manual port forwarding: Configure router if UPnP unavailable

​
Accessing NetPlay

1

Open NetPlay

Click Tools > Start NetPlay in the main menu
2

NetPlay Window

The NetPlay setup window appears with options to host or join

​
Hosting a NetPlay Session

​
Creating a Session

1

Host Tab

In the NetPlay window, click the Host tab
2

Configure Settings

Set your session parameters:
  • Traversal Server: Enable for easy connection (recommended)
  • Host Port: Default 2626 (change if needed)
  • Host Code: Generated for Traversal Server method
3

Start Hosting

Click Host to create the session
4

Share Code

Share the Host Code with players (Traversal) or your IP address (Direct)

​
Connection Methods

​
Host Options

​
Session Settings

  • Session Name: Descriptive name for your session
  • Password: Optional password protection
  • Limit Players: Maximum number of players (2-4 typically)

​
Game Configuration

Before starting:
  • Select the game from your library
  • Configure which controllers are used by each player
  • Adjust buffer size (see Lag Mitigation)

​
Configuring Player Controllers

1

Assign Controllers

In the NetPlay window, assign GameCube/Wii controllers to players:
  • Port 1-4 for GameCube controllers
  • Wii Remote 1-4 for Wii games
2

Set Controller Type

For each port, select:
  • None: No controller
  • Standard Controller: GameCube controller
  • GBA: Game Boy Advance
  • Player 1, 2, 3, 4: Assign to specific player

​
Joining a NetPlay Session

​
Joining via Traversal Server

1

Connect Tab

In the NetPlay window, click the Connect tab
2

Enter Host Code

Enter the Host Code provided by the host
3

Connect

Click Connect
4

Wait for Sync

Wait for session to sync (host will configure settings)

​
Joining via Direct Connection

1

Connect Tab

Click the Connect tab
2

Uncheck Traversal

Uncheck Use Traversal Server
3

Enter Address

Enter the host’s IP address and port (e.g., 192.168.1.100:2626)
4

Connect

Click Connect

​
NetPlay Configuration

Configure NetPlay settings in Options > Configuration > NetPlay (or via NetPlay window settings):

​
Connection Settings

  • Traversal Server: stun.dolphin-emu.org (default)
  • Traversal Port: 6262 (default)
  • Traversal Port (Alternate): Backup port if primary unavailable

​
Buffer Size

Controls input lag to compensate for network latency:
  • Lower (1-5 frames): Less lag, requires very good connection
  • Higher (6-15 frames): More stable, higher input delay
  • Auto-adjust: Dolphin can adjust based on connection quality
Use 2-4 buffer size for minimal input lag.
Buffer size adds frames of input lag. Lower is better, but too low causes stuttering and desyncs.

​
Save Data Synchronization

  • Load Savedata: Use host’s save data for all players
  • Write Savedata: Allow saving during NetPlay
  • Sync All Wii Saves: Synchronize all Wii save data (not just current game)
Enabling write savedata during NetPlay can corrupt saves if desyncs occur. Use with caution.

​
Code Synchronization

  • Sync Codes: Ensure all players use same Gecko/AR codes
  • Required for competitive play

​
Network Mode

Choose netplay timing mode:
All players experience same input lag based on slowest connection.
  • Recommended for competitive play
  • Ensures fair gameplay
  • Everyone has identical experience

​
Other Settings

  • Record Inputs: Save NetPlay inputs for replay analysis
  • Strict Settings Sync: Enforce identical settings on all players
  • Golf Mode Overlay: Show turn indicator in Golf Mode
  • Enable QoS: Prioritize NetPlay traffic (Quality of Service)
  • Use UPnP: Automatic port forwarding

​
Starting the Game

Once all players are connected:
1

Host Configures

Host selects game and configures settings
2

Assign Controllers

Host assigns controller ports to each player
3

Start Game

Host clicks Start to begin emulation
4

All Players Sync

All players’ Dolphin instances sync and start the game
The game must be in each player’s configured game directories. Dolphin will detect if all players have matching game files.

​
During NetPlay

​
Chat

Communicate with other players:
  • Built-in text chat in NetPlay window
  • Messages appear for all players
  • Useful for coordination

​
Pause and Resume

Host can pause emulation:
  • Useful for breaks or configuration changes
  • All players pause simultaneously

​
Save States (Host Only)

Host can create and load save states:
  • All players sync to the same state
  • Useful for retrying difficult sections
  • States are session-specific
Save states in NetPlay are controlled by the host. Clients cannot independently save or load.

​
Kicking Players

Host can remove players:
  • Right-click player in player list
  • Select Kick Player

​
Lag Mitigation

​
Optimizing Buffer Size

1

Start with Auto

Begin with automatic buffer adjustment
2

Monitor Performance

Watch for stuttering or slowdowns
3

Adjust Manually

Increase buffer if desyncs occur, decrease if input lag is too high
4

Test

Test in non-critical gameplay moments

​
Connection Quality

Check connection quality:
  • Ping indicator: Shows latency to other players
  • Desync warnings: Alert when synchronization issues occur
Enable Show NetPlay Ping in Graphics settings to display ping on-screen during gameplay.

​
Reducing Lag

  • Close bandwidth-heavy applications
  • Use wired Ethernet instead of Wi-Fi
  • Connect to geographically close players
  • Reduce buffer to minimum stable value
  • Disable background downloads/uploads

​
Spectator Mode

Watch NetPlay sessions without playing:
1

Join as Spectator

Connect to session normally
2

No Controller Assigned

Host assigns no controller ports to spectator
3

Watch

Spectator can watch gameplay without affecting synchronization

​
Troubleshooting

​
Connection Failed

If unable to connect:
1

Verify Versions

Ensure all players use identical Dolphin version
2

Check Code/IP

Verify host code or IP address is correct
3

Port Forwarding

For direct connection, confirm port 2626 is forwarded
4

Firewall

Check firewall isn’t blocking Dolphin
5

Try Traversal

If direct fails, try Traversal Server method

​
Desynchronization

Desyncs cause players’ games to diverge, breaking multiplayer.
Causes of desyncs:
  • Different game versions or ISOs
  • Different Dolphin settings
  • Unstable connection
  • Gecko codes or patches not synced
Solutions:
  1. Verify MD5/SHA-1 hash of game files match
  2. Enable Strict Settings Sync
  3. Disable all codes unless synchronized
  4. Increase buffer size
  5. Restart session if desyncs persist

​
High Input Lag

If input delay is too high:
  • Reduce buffer size incrementally
  • Use wired internet connection
  • Close background applications
  • Choose geographically closer host
  • Consider if connection is suitable for NetPlay

​
Poor Performance

If NetPlay runs slowly:
  • Host: Ensure adequate CPU for game + NetPlay overhead
  • All players: Close unnecessary programs
  • Lower graphics settings (internal resolution, enhancements)
  • Ensure emulation reaches 100% speed
NetPlay requires all players to maintain 100% emulation speed. The slowest player determines session speed.

​
Game Doesn’t Start

If game fails to launch:
  • Confirm all players have the game
  • Verify game files are identical (check file size and hash)
  • Ensure game is in configured ISO directories
  • Check for missing BIOS or system files

​
Compatible Games

Most GameCube and Wii games work with NetPlay:
  • Best: Local multiplayer games (Mario Kart, Smash Bros, Mario Party)
  • Good: Co-op games, split-screen titles
  • Limited: Games with heavy randomization or complex timing
  • Not Compatible: Games requiring original online services, Wii Speak, or specific peripherals
Check the Dolphin Wiki for game-specific NetPlay compatibility and recommended settings.

​
Best Practices

​
Before Starting

  1. Verify all players have matching game files
  2. Use same Dolphin version (check About > Dolphin)
  3. Configure settings before connecting
  4. Test connection with a short session first

​
During Play

  1. Host should have the fastest CPU
  2. Use Fair Input Delay for competitive games
  3. Communicate via chat for coordination
  4. Save states for checkpoints in co-op games
  5. Monitor ping and adjust buffer as needed

​
For Best Experience

  • Connection: Wired Ethernet, < 50ms ping
  • Buffer: Lowest stable value (test and adjust)
  • Settings: Moderate graphics settings for stability
  • Players: Geographically close for lower latency