Choose a camera
Allow a built-in or connected camera in your browser.
RAPID CACTUS
Turn any webcam into a private motion detector.
No install, account, or video upload.
Detect movement locally, focus on useful areas with Watch and Ignore zones, and choose whether to save event evidence in this browser.
The Webcam Test asks for video only after you press Start, keeps analysis in this browser, and does not open the detector camera for you. See how privacy works.
- Runs locally in your browser
- No account or cloud video
- Watch and Ignore zones
A real detector view
Monitor the area that matters. Ignore movement that does not.
Define zones
Watch the door or workspace while excluding busy areas.
Start monitoring
See live motion strength and save local event evidence when enabled.
The detector opens with the camera in standby and only starts after you choose to monitor.
Use cases
A spare camera can do useful work
Reuse an old laptop
Use its built-in camera as a local monitor near an entry, shelf, or room.
Read the setup guide →Set up an entry view
Focus on a door or gate while excluding streets and windows.
Plan entry zones →Monitor a pet area
Watch activity around a crate, feeding area, or pet door without recognition.
See pet-area boundaries →Watch a workshop area
Focus on a bench, shelf, or doorway without treating it as a safety system.
Set up a workshop view →Test motion sensitivity
Measure local Motion Strength and choose a sensible starting threshold.
Calibrate your camera →Webcam motion detector setup
Follow the full local path from a built-in or connected webcam to monitoring.
Read the setup guide →Private by design
Your camera feed stays with you
Camera analysis happens on your device in the browser. Live video is not uploaded to Rapid Cactus servers. Settings and saved snapshots remain in the browser until you explicitly export or clear them.
No account requiredNo cloud videoYou control exports
Keep the page and device active while monitoring. Rapid Cactus is a lightweight local monitor, not a certified security system.
Before you start
What you need
Use Rapid Cactus from a secure HTTPS page in a browser that can request camera permission. Keep the browser page open and the device awake while monitoring. The detector asks for camera access only when you press Start monitoring.
Privately check the camera with the Webcam Test first if you want. For long sessions, read the keep a laptop awake guide. If permission is blocked, use the camera permission guide.
Quick answers
Questions before you monitor?
Is Rapid Cactus free and account-free?
Yes. You can open the detector without creating an account.
Is live video uploaded?
No. Motion analysis runs locally in your browser, and live video is not uploaded to Rapid Cactus servers.
Does it work if the browser is closed?
No. Keep the browser page and device active while you want it to monitor. See the operating guide.
Ready when you are