Explainer
What is latency in real-time face swap?
Latency is the delay between an action on camera and the swapped frame that shows it. What contributes, what you control, and what cannot be promised.
The definition
Latency is the time between something happening and you seeing the result. In a live face swap, the event is usually your own movement on camera and the result is the matching frame in the output panel. When the output trails your hand by a beat, that gap is latency.
It is easier to notice than to measure from the outside, because the delay you experience is the whole path, not one component of it. For a conversation a small delay is easy to ignore; for a timed performance it changes how you move. The same gap feels different depending on what you are doing.
Where the delay comes from
A live frame passes through several stages, and each one adds a little time.
- Capture: the camera exposes a frame and the browser receives it.
- Encoding: the frame is compressed for the trip.
- Network: frames travel to the cloud session and back, and distance, congestion and Wi-Fi all add up.
- Model time: the cloud session renders the swapped frame.
- Display: the browser decodes and shows the video, and the screen refreshes on its own schedule.
Latency is not frame rate
Frame rate is how often the output updates; latency is how far behind each update is. A stream can update smoothly and still be a beat behind, or update rarely without much lag. Both matter to how live the result feels, and both depend on the same path.
What you can control
You cannot remove network distance, but you can make the path better.
- Use a wired connection or a strong Wi-Fi signal close to the router.
- Close bandwidth-heavy downloads, streams and tabs while you are live.
- Keep the laptop plugged in and avoid heavy background applications.
- Give the camera good light so it does not have to work in the dark.
- Use a current desktop browser and keep the session in the foreground.
What we cannot promise
There is no single latency figure that holds for every user, network and browser, so we do not publish one. Your result depends on your connection and your machine. If the delay bothers you, improve the network path first: it is usually the largest variable you own.
What we can say is that the path is shared. A change that shortens one session — a better connection, less browser load, a stable frame rate — usually improves the next one too.
FAQ
- What latency should I expect?
- It depends on your connection, your browser and the cloud session. The path adds up from capture, encoding, network, model time and display, so a single figure would not be honest for every setup.
- Why does the output lag more sometimes?
- Congestion and jitter change from minute to minute. Another device on the network or a busy browser can make the same session feel slower than it did an hour earlier.
- Does a better GPU reduce latency?
- No. The model runs in the cloud session, so a local graphics card does not shorten the path.
- How do I tell latency apart from stutter?
- Latency is a consistent delay: the output moves with you but a beat behind. Stutter is uneven updates: some frames arrive late or not at all.