What Is NDI?

If your streaming setup involves more than one computer, moving video between them is usually the hard part. HDMI cables only stretch so far, and a second PC in another room means running cable through walls or giving up on the idea entirely.

NDI takes a different approach. Instead of sending video down a dedicated cable, it sends video, audio, and control data across the network you already have. This guide covers what NDI is, why it exists, when it makes sense for a streaming setup, and how it compares to capturing over HDMI.

NDI stands for Network Device Interface. Originally developed by NewTek and now owned by Vizrt, it is a protocol that lets devices and software send video and audio to each other over a standard IP network, using the same ethernet cables and switches that carry the rest of your traffic.

The problem it solves comes from live production. Traditional video connections are point to point: one cable, one source, one destination. Adding a camera means adding a cable. Moving a source across a building means running a longer cable, or converting the signal to something that travels further. In a studio with a dozen sources, that becomes a lot of physical infrastructure that is expensive to install and slow to change.

NDI removes the dedicated cable from that equation. Any device on the network can send a video stream, and any device on the network can receive it. Adding a source means putting it on the network, not running new cable. Rearranging a production means changing what receives what in software.

That approach started in broadcast and live events, where the flexibility is worth the setup. It has since worked its way into home setups, where the same benefit applies at a smaller scale: your gaming PC and your streaming PC can be in different rooms and still work together.

NDI encodes video and audio on the sending device, sends it across the network as data, and decodes it on the receiving device. Discovery is automatic on most local networks, so a source that starts broadcasting shows up as an available input on other machines without manual IP configuration.

Two things matter for whether this works well:

• Bandwidth. Full NDI is designed for quality over compression, so each stream uses a meaningful chunk of a gigabit connection. Multiple simultaneous streams add up quickly. For connections with less headroom, the NDI HX family compresses more heavily. HX and HX2 trade latency for much lower bitrates, while HX3 sits closest to full NDI on latency while still using a fraction of the bandwidth.
• Network quality. Wired ethernet is strongly preferred. Wi-Fi introduces variability that shows up as dropped frames or stutter, especially on a busy home network. A gigabit switch between the two machines gives you a more predictable result than routing everything through a shared router.

Latency is low but not zero. On a wired gigabit network the NDI stream itself runs sub-frame, closer to a frame or two once capture and software processing are added in. For a dual PC streaming setup, where the sending machine is running the game and the receiving machine is running the encoder, that delay sits in the stream path rather than in what you see while playing. For anything where you are reacting to the NDI feed in real time, it is worth testing before committing to it.

The clearest case is distance. If your second PC lives on another floor, in another room, or anywhere a standard HDMI cable does not reliably reach, NDI turns a wiring problem into a networking problem. Passive HDMI cables are only reliable to about 25 feet, less at 4K, so distance is usually what decides it. Ethernet runs further than HDMI, and most homes already have some of it in place.

It also helps when your setup changes often. If you regularly move machines around, add a laptop for a specific project, or want a phone or tablet acting as an extra source, NDI handles that without new hardware for each addition.

It is worth considering if you already own the networking gear. NDI software itself is free, including NDI Tools and the plugins that let it work with common streaming applications. If your PCs are already wired to a gigabit switch, the cost of trying it is your time.

Both approaches solve the same problem, getting video from one machine to another, but they solve it differently and the trade-offs are real. In short: NDI works best for computer sources on a wired network, while a capture card is the better fit for consoles, cameras, and any HDMI source. The practical split comes down to what you are capturing and how predictable you need it to be.

NDI works well when your source is a computer. It is flexible, needs no additional hardware, and scales to more sources without more cables. What you give up is independence from your network. If someone starts a large download, or your switch is saturated, that shows up in your stream.

A capture card works well when your source is anything with an HDMI output, and when you want the video path to behave the same way every session. Consoles are the obvious case, since a PlayStation or Xbox has no way to send NDI, but the same applies to cameras and to PCs where you would rather not add network traffic to the equation. If you are still deciding whether you need one at all, our guide on whether a capture card belongs in your setup walks through the question, and what a capture card does covers the fundamentals.

Plenty of setups use both. Video comes off a console through a capture card, and a second computer contributes a software source over NDI.

The general path looks the same across most setups:

1. Install the NDI Runtime on both machines. The simplest way to get it is NDI Tools, a free bundle that also includes utilities for sending, receiving, and testing that discovery works.
2. Connect both machines to the same local network, ideally wired to the same switch.
3. Add the NDI plugin for your streaming software. For OBS Studio this is DistroAV, renamed from obs-ndi in 2024 — a separate community plugin rather than a built-in feature. Current versions require a recent OBS build and the NDI 6 runtime.
4. On the sending machine, start an NDI output.
5. On the receiving machine, add an NDI Source in your streaming software and select the sending machine from the list of discovered sources.

Important: If sources do not appear, the cause is usually network isolation rather than a broken install. Guest network segments, VLANs, and some mesh Wi-Fi systems block the discovery traffic NDI relies on. Putting both machines on the same wired segment resolves most of these cases. If they have to live on different subnets, the NDI Discovery Server lets you point both machines at a fixed address instead of relying on automatic discovery.

NDI carries audio alongside video, which covers the basic case. Where it gets more involved is when you want separate mixes: game audio at one level for you and another for your stream, voice chat isolated from the recording, music that ducks under your voice.

That kind of routing is a different problem from moving video between machines, and it is usually solved on the audio side rather than the video side. Wave XLR Pro handles dual PC audio in hardware, with independent mixes running at the same time, which our article on Wave XLR Pro and dual PC streaming covers in detail. For a software approach to the same problem, Wave Cast is built specifically for dual PC audio.

Worth knowing: no Elgato hardware sends or receives NDI directly. If NDI is part of your video path, your audio path can still run separately through whatever handles it best.

NDI is worth trying if your second machine is a computer, your network is wired, and distance is the thing standing in your way. If your source is a console or a camera, or you need the video path to behave identically every session, a capture card is the more direct answer. Our capture card comparison breaks down which one fits which setup.