Two free AI-powered posture apps compared. Both use your webcam to detect poor posture — but they take different approaches to what happens next.
Crane and SitApp are both free desktop applications that use AI and your webcam to monitor your posture in real time. Both run entirely offline, meaning no video data ever leaves your machine. Where they differ is in scope: SitApp focuses purely on posture detection and slouch alerts, while Crane layers structured ergonomic break cycles on top of its posture monitoring.
SitApp is a focused, lightweight posture detection tool. It watches your posture via webcam and pops up a reminder when you slouch. It includes posture statistics so you can track improvement over time and supports standing desk setups. Notably, SitApp supports Linux in addition to Windows and macOS — a platform Crane does not yet cover.
Crane also detects posture via webcam using TensorFlow.js (MoveNet), but it adds a structured ergonomic cycle system. The app includes 15 research-backed profiles that guide you through sequences of sitting, standing, walking, stretching, and exercise activities across 60-minute cycles. This means Crane does not just tell you when your posture is poor — it proactively schedules movement variety throughout your day.
| Feature | Crane | SitApp |
|---|---|---|
| AI posture detection | Yes (MoveNet) | Yes |
| Ergonomic break cycles | Yes (15 profiles) | No |
| Activity types | 5 (sit, stand, walk, exercise, stretch) | N/A |
| Research citations | 30+ peer-reviewed | Not specified |
| Posture statistics | No | Yes |
| Standing desk support | Yes (stand activities) | Yes |
| Windows | Yes | Yes |
| macOS | Yes | Yes |
| Linux | No | Yes |
| Price | 7-day trial, then $54.99 one-time | Free |
| 100% offline | Yes | Yes |
| Dark mode | Yes | Not specified |
| Languages | 17 | Not specified |
Choose SitApp if you want a focused, free slouch detection tool — especially if you need Linux support. SitApp does one thing and does it well: it watches your posture and alerts you when you slouch.
Choose Crane if you want posture detection combined with guided ergonomic break cycles. Crane's 15 research-backed profiles schedule sit, stand, walk, stretch, and exercise activities across your workday — going beyond detection into active posture management.
All information based on publicly available sources as of March 2026. Features may change. This comparison is intended to be fair and factual.