How to Configure Netplay for Online Multiplayer in RetroArch

RetroArch netplay allows you to play classic games with friends over the internet, but proper configuration is essential for a smooth experience. This guide walks you through the necessary steps to host or join a multiplayer session, ensuring both players have matching content and core settings. You will learn how to navigate the netplay menu, manage port forwarding, and adjust delay frames to minimize lag during your online gaming sessions.

Prerequisites for Connection

Before attempting to connect, both players must ensure their installations are synchronized. This means using the exact same core version and the same game content file. Even minor differences in ROM hashes or core settings can prevent a successful connection or cause desynchronization during gameplay. It is recommended to update RetroArch to the latest version on both machines to avoid compatibility issues.

Hosting a Netplay Session

To host a game, launch RetroArch and load the core and content you wish to play. Navigate to the Main Menu and select Netplay, then choose Host. You will be prompted to select a port, with 55435 being the default standard. Once hosted, your IP address will be displayed, which you must share with your friend so they can join. Ensure your firewall allows UDP traffic on the selected port to prevent connection blocks.

Joining a Netplay Session

The second player should open RetroArch and go to the Main Menu, selecting Netplay followed by Join. Enter the IP address provided by the host and confirm the port number matches. If the host is using a password, enter it when prompted. Upon connecting, the guest will download the necessary content from the host if the Content Directory is configured correctly, ensuring both sides are running identical data.

Optimizing Performance and Latency

Lag is the most common issue in online emulation, but it can be mitigated through delay frames. In the Netplay settings, both players should adjust the delay frames to balance responsiveness with stability. Higher numbers reduce stuttering but increase input lag. Additionally, hosting the session on the machine with the best upload speed and using a wired Ethernet connection instead of Wi-Fi will significantly improve stability for both participants.

Troubleshooting Common Issues

If you cannot connect, verify that port forwarding is set up correctly on the host’s router for UDP port 55435. Check that both players have disabled any conflicting overlays or shaders that might affect performance. Finally, ensure that neither player has paused the game inadvertently, as pausing during netplay will freeze the session for everyone involved.