Vigilo: Turn an Old Phone Into a Free Security Camera

There's a drawer in almost every home where old phones go to be forgotten. Mine holds at least two that still work perfectly, and every time I open it I feel a small pang of guilt. All that camera hardware, all those sensors, sitting in the dark doing nothing. So when I stumbled across Vigilo while digging through GitHub for a subscription-free way to reuse an old phone as a camera, it felt like the drawer had finally answered back.

Vigilo is a free, open-source web app that turns any device with a camera into a motion-detecting security camera. There is nothing to install from an app store and no account to create. You open vigilo.eifr.dev on the old phone, allow camera access, prop it up facing the door, and that's the setup done. The whole thing runs in the browser, and since it's a progressive web app you can add it to the home screen so it behaves like a native app.

Everything stays on the device

Here's the part that made me look twice: there is no cloud. The video feed is processed locally on the phone itself, settings live in the browser's local storage, and nothing is uploaded to some company's server farm. For a camera pointed at the inside of your home, that's exactly the architecture I'd want. There's no footage to leak in a data breach, because no footage is stored anywhere but with you.

The AI runs in your browser

Detection comes in two flavors. The default is smart object detection powered by an EfficientDet-Lite AI model that runs directly in the browser, preferring your GPU with an automatic CPU fallback. It recognizes specific objects, with person tracking switched on out of the box, and you can tune the confidence threshold and how many results it reports. There's even a test mode where you upload any image to watch the detection work before trusting it with your hallway.

If you'd rather keep things light, you can switch to a classic pixel-motion mode built on OpenCV.js, with sliders for sensitivity, the ratio of pixels that need to change, and how often it checks. Simple, fast, and gentle on older hardware.

My favorite detail is Low Light Vision. If movement is detected in the dark, Vigilo can fire the phone's flashlight (or light up the screen at full brightness) for a few seconds so the snapshot actually shows something. That's the kind of small, clever feature that usually hides behind a paywall.

Telegram becomes your security feed

Instead of building yet another notification app, Vigilo piggybacks on Telegram. You create a free bot with @BotFather, paste the token in, and from then on every motion event lands in your Telegram chat as a message with a snapshot attached. A debounce setting keeps it from spamming you when the cat decides to practice parkour.

It goes both ways, too. You can reply to an alert to tell Vigilo to start or stop tracking that type of object, and sending the word "status" to your bot gets you a reply confirming everything is operational. And if the internet drops, alerts queue locally on the device and send once the connection comes back.

Where to be careful

Vigilo is a very young project, and it shows in a few places. The browser tab needs to stay open and the phone needs to stay awake, so plan on keeping it plugged in full time. It sends snapshots on motion, not continuous video recording, so if you need a 24/7 timeline to scrub through, a traditional camera system fits better. Remote check-ins happen through those Telegram snapshots rather than a live feed you open from anywhere. For a one-person open-source project, though, the polish is genuinely impressive.

The verdict

Vigilo won't replace a professional security setup, but that's not the job it applied for. It takes the phone you already paid for and turns it into a private, subscription-free watcher for your front door, your plants, or the mystery of who keeps finishing the orange juice. The code is MIT-licensed and lives on GitHub at https://github.com/eifr/Vigilo, where the project is still early but actively developed. The junk drawer just got a promotion.