KamaePrivacy in webcam posture apps: how to check before you install — Kamae
If you are thinking about installing a posture app that uses your Mac's camera, you are right to ask what happens to the video. This guide is the short version: the two ways these apps handle your camera, the four things worth checking before you install one, and how Kamae keeps video on your Mac.
The short answer is that a well-built webcam posture app analyses each frame in memory on your Mac and throws it away immediately, so video never leaves your Mac. A poorly built one uploads frames to a server for analysis. The difference is not subtle. If the app needs the internet to do its analysis, your video leaves your Mac.
The two approaches
Webcam-based posture apps fall into two camps:
- On-device only. Each frame is read in memory, turned into a few numbers (how far your neck has dropped, how close you are to the screen, how tilted your shoulders are), compared with a baseline you set, and discarded. Nothing is saved and nothing is uploaded during monitoring. The app may still go online for non-camera things — checking a license, looking for updates — but never to send frames.
- Server-side analysis. Each frame is sent to a remote server, where heavier computer-vision models turn it into posture data, and the result comes back to the app. This usually gives the company a more accurate model, but it also means every frame of you sitting at your desk goes over the network. That is not a posture app; that is a webcam service with a posture feature.
There is no middle ground. If the app needs the network to do its analysis, your video leaves your Mac. If it does not, your video stays.
Some apps also fall back to a sit timer when no camera is available — a clock that just reminds you to stand up. That mode never sees you at all, and there is nothing to leak.
Four things to check before you install
You do not need to read source code. Four quick checks are enough to tell which camp an app is in.
### 1. Read the privacy screen, exactly
Open the app's privacy or settings screen and look for a clear statement in plain language. Look for words like "frames are processed on-device" or "video is never uploaded" or "no images are stored". If the language is vague — phrases like "your data may be used to improve our service" or "we use industry-standard analytics" — read it as a no.
### 2. Watch the camera light
On a Mac, the camera light is hardware-controlled and cannot be switched off in software. If the light is on, the camera is producing data, and something on your Mac is receiving that data. Run the posture app for a few minutes and watch the light.
A well-built app opens the camera for about a second at a time, every thirty seconds or so, and the light blinks in step with that pattern. A bad app keeps the light on continuously because it is streaming frames somewhere.
If the app lets you set the cadence, set it to once every thirty seconds and confirm the light blinks accordingly. If the light stays on, the app is using the camera more than it needs to.
### 3. Watch the network
Open a network-monitoring tool — macOS has one built into the network utility, and there are simple free ones — and run the posture app for a few minutes. You should see connections only when the app does non-camera things: checking a license, looking for updates, sending a feedback report when you ask it to.
If you see a steady stream of small outbound packets while the camera is active, that is frames being uploaded.
### 4. Check the in-app connection log
A good app will let you see, inside the app, the list of connections it has actually made. Look for a screen called "Connection log", "Network log", "Privacy log", or similar. If it lists every connection with a timestamp and a destination, and you can recognise all of them as license checks, update checks, and feedback you sent, you are in the clear. If the log is missing, hidden, or only available to the developer, that is a red flag.
How Kamae handles your camera
Kamae is built for the on-device camp. There is no Kamae server.
Each frame is read in memory, turned into three numbers — how far your neck has dropped, how close you are to the screen, how tilted your shoulders are — compared with the baseline you set, and thrown away. No image is saved. No video is uploaded. The Mac's camera light is on only during the brief moment Kamae is looking, which by default is about one second every thirty seconds. If you are slumped, Kamae checks more often — every ten seconds. On battery, it checks half as often.
There is no telemetry, no analytics, no install IDs, and no A/B testing. We do not know how many people use Kamae, what features they click on, or what country they are in. We would rather ask you than watch you.
Kamae does go online, but only for three things, and only when it needs to:
- License check. When you enter a license key, and occasionally afterwards, to confirm the key is still valid with our reseller, Polar. This is a single small request and the response is cached on your Mac.
- Update check. Once a day, Kamae asks our update server whether a new version is available. The request includes only your current version number.
- Feedback. Only when you choose to. Settings → Feedback lets you send a message, an error report, or both. Nothing is sent until you press the button.
You can see every connection Kamae has made, with a timestamp and destination, in Settings → Privacy → Connection log. If something appears in that log you do not recognise, that is a bug and we want to hear about it.
If you turn off your network entirely, Kamae keeps working as a posture monitor. It will show a warning that update and license checks cannot run, but the camera analysis does not need the network.
CPU and battery
Kamae is light enough that you do not notice it on a modern Mac. On an M4 Mac mini running for an hour with the camera sampling at the default rate, Kamae's CPU averaged 0.5%. On a MacBook on battery, the camera samples half as often so the cost is even lower. The camera is the most expensive thing Kamae does, and it is on for about one second every thirty seconds.
What Kamae is not
Kamae is not a medical device. It is a habit tool that helps you notice how you sit. It does not diagnose, address, or prevent any condition. If you have pain, please see a professional.
Kamae is also not anonymous telemetry. If you choose to send a feedback report, it goes to a real human at FUNBREW with the message you wrote, the app version, the macOS version, and nothing else.
Try it
Try Kamae
Kamae is a Mac menu bar app that quietly watches your posture through the camera. Video never leaves your Mac. Try it free for 14 days, or buy it once for US$19.