The guides below can't be used to stream DS games, DSiWare, and GBA games. You will need a hardware capture card to do that.
This page will show you how to stream your 3DS console's screens to your computer over WiFi. For both methods, keep the following things in mind;
Your console and your computer need to be on the same network.
Streaming audio over WiFi currently isn't possible, you will need to use an AUX cable and a device with Line In to receive audio.
If you have a poor connection, you may not get the best results.
While you shouldn't stream from an Old 3DS console due to the very low frames you will get, the section is still here as a 'proof of concept' thing that you can mess around with. It is not intended for practical use.
Finding your Console's IP
This section is crucial if you want to stream. You should follow this first, regardless of what streaming method you choose.
Section I: Finding your IP with FBI
Open FBI on your console
Use the D-Pad to scroll down to Remote Install and press A
Select Recieve URLs over the network
Your console's IP should now be on screen, take note of it
This IP is a local IP for your device and it is not your actual public IP
Section II: Finding your IP with the Homebrew Launcher
Open the Homebrew Launcher on your console
Press Y
Your console's IP should now be on screen, take note of it
This IP is a local IP for your device and it is not your actual public IP
Streaming with NTR+Snickerstream (recommended)
This method is not possible with Old 3DS models. You will need to follow the HzMod guide below.