Your posture is bad right now.
Your Mac already has a camera pointed at your face. Posture uses it to catch the slow slide forward, says one thing, then shuts up.
Free, signed and notarized. Drag it to Applications and you are done.
macOS 14 Sonoma or later · Apple silicon · MIT licence
The problem
Nobody decides to sit badly.
At nine your back is against the chair. At eleven you lean in to read something small and forget to lean out. By three your chin is past your collarbone, your shoulders have rolled forward, and the only thing that will mention it is the ache at six.
The slide is too slow to feel. That is the whole difficulty: it is not a decision you can make better, it is a drift you cannot see. Every reminder app gets this wrong by buzzing on a timer: at minute thirty it buzzes, whether you are folded over the keyboard or sitting like a violinist.
A timer does not know how you are sitting. Something has to look.
How it works
Three steps, then it gets out of the way.
- 01
Sit how you want to sit. Press Calibrate.
Posture stores a handful of numbers describing that pose: the angle of your neck, the height of your shoulders in frame. Not a photo. Numbers.
- 02
It watches the angle, not you.
Every few seconds it finds the same landmarks and compares them to your baseline. That comparison is the entire product. It has no idea what you look like or who else is in the room.
- 03
You drift. It says one thing.
A single banner, once. You sit back and it goes quiet. Nothing to dismiss, nothing to keep up, nothing waiting for you tomorrow morning.
Inside the app
There is no app window. That is the point.
Posture is a square in the menu bar and, rarely, one notification. Everything it has to say fits in these three moments.
Good posture
Recalibrate
Pause for an hour
Quit Posture
Calibrating 6/10, hold still
Sit the way you actually want to sit. Ten samples become your baseline: a few numbers, never an image.
Posture
You have been slouching for a while. Sit up.
Privacy
A camera app you can leave on.
Pointing a webcam at yourself all day is a big ask, and it should be. Here is the entire answer to “where does the video go?”
- 0
bytes uploaded
The app ships with no network entitlement, so macOS refuses to open a socket for it.
- 0
accounts
No email, no licence key, no sign-in screen. You open the app and it works.
- 1
nudge, then silence
One banner when you drift. No streak, no daily score, no badge turning red.
Nothing is uploaded
The app ships without the network entitlement. It is not that Posture chooses not to phone home: it cannot. macOS will not let it open a socket.
Nothing is recorded
Frames are read, measured and discarded in memory. No image is ever written to disk, not even a thumbnail, not even temporarily.
Nothing is an account
No sign-up, no email, no licence server, no analytics SDK. You download an app and it works. That is the whole relationship.
Instead of
The other three ways to fix your back.
| Capability | Posture | A brace | A cloud app | Willpower |
|---|---|---|---|---|
| Nothing to wear | Yes | No | Yes | Yes |
| Notices without you thinking about it | Yes | Yes | Yes | No |
| Camera feed stays on the machine | Yes | Yes | No | Yes |
| Works with the Wi-Fi off | Yes | Yes | No | Yes |
| No account to create | Yes | Yes | No | Yes |
| You can read every line that runs | Yes | No | No | No |
Price
$0
Free, and staying free.
Charging would mean a licence server, a payment flow and an account system, three things that each need the network access this app deliberately does not have. The price is not a promotion. It is the architecture.
- Every feature. There is no locked tier.
- No subscription, no renewal, no card.
- No account, so nothing to cancel.
- MIT licence. Fork it, ship it, sell it.
Questions
Reasonable suspicions, answered.
Is any video sent anywhere?
No. The app has no network entitlement at all, so macOS blocks it from making connections even if it tried. Frames are analysed in memory and dropped immediately.
Why is it free?
It is a menu bar app that compares two angles. Charging for it would mean building a licence server, a payment flow and an account system, three things that would each need the network access this app deliberately does not have. Free and MIT is the honest shape for it.
Does it work in bad lighting?
It needs enough light for macOS to find a face, roughly what you would need for a video call. In a dim room it reports that it cannot see you rather than guess.
Will it eat my battery?
It samples a few frames per minute rather than running a live video stream, and the work happens on the efficiency cores. When the lid is shut or no face is in frame, it stops sampling.
Can I use an external webcam?
It is designed around the built-in camera, since that sits at a known angle relative to the screen. External cameras that macOS exposes should work, but calibration matters more.
Windows or Linux?
Not planned. The pose detection leans on Apple’s Vision framework, which does the hard part on-device for free. Rebuilding that elsewhere would be a different project.
When can I download it?
Now. The download button on this page always serves the newest release: a signed and notarized DMG. Open it, drag Posture to Applications, and grant camera access when macOS asks. Every release also lives on the GitHub releases page with its changelog.