How to Turn Your Old iPhone Into a 4K Dashcam

An old iPhone makes a genuinely good dedicated dashcam, the camera and stabilization are usually better than a budget hardware unit, and it costs nothing extra. iOS just needs a handful of specific settings changed first, because Apple's default power-management behavior is built around a phone you carry and check, not one that sits mounted and recording for an hour at a time.

1. Update iOS first

Update to the latest iOS version the phone supports before doing anything else. Camera permission handling and background activity rules have changed across iOS versions, and starting from a current version avoids chasing down version-specific quirks later.

2. Turn off auto-lock

Go to Settings → Display & Brightness → Auto-Lock and set it to Never while the phone is dedicated to dashcam duty. iPhones default to locking the screen after a short idle period, and while Dashoo's recording continues in the foreground, a locked screen sitting on your dashboard is a bad look and makes it harder to glance at speed or tap the incident flag quickly. Since the phone will be permanently powered, battery drain from the screen isn't the concern it would normally be.

3. Disable Low Power Mode

Low Power Mode reduces background activity and throttles performance to extend battery life, useful day to day, actively counterproductive here. Go to Settings → Battery and make sure it's off. With the phone on a car charger the whole time, there's no battery to protect.

4. Check camera and microphone permissions

Install Dashoo from the App Store and grant camera, microphone, location, and photo library access when prompted. If you skip any of these during setup, iOS won't ask again automatically, you'll need to go to Settings → Dashoo and enable them manually.

5. Mount it and connect power

A basic windscreen or dashboard mount is enough. For power, use a Lightning or USB-C car charger depending on your iPhone model (USB-C for iPhone 15 and later). Continuous 4K recording is one of the most demanding things you can ask an iPhone to do, on battery alone, expect roughly 90 minutes before it needs a break. Plugged in, it'll run for as long as the car is on.

6. Start recording

Tap record before you pull off. GPS speed and location, plus G-force readings, log automatically from there. If something happens, tap once to flag the clip so it's protected from loop recording and won't get overwritten later.

A note on Face ID and interruptions

If the phone locks for any reason while mounted, unlocking it with Face ID means glancing at the phone, not ideal while driving, but with auto-lock disabled per step 2, this shouldn't come up during normal use. Incoming calls and notifications can still interrupt the camera view depending on iOS version, worth testing once before you rely on it for a long drive.