Use a stud-finder smartphone app

Download a stud-finder app (e.g., Walabot DIY, Stud Finder by Tavendo) on your smartphone. These apps use the phone's built-in magnetometer or, with an accessory sensor, radio-frequency imaging to detect changes in wall density. Hold the phone flat against the wall and slide it slowly across the surface, following the app's on-screen prompts.

Why It Works

Most smartphones contain a magnetometer (compass sensor) that can detect the steel screws and nails securing drywall to studs — the same principle as a rare-earth magnet, digitized. Accessory-based apps like Walabot DIY ($60-100) clip onto the phone and use RF imaging to detect studs, pipes, and wires through drywall up to 4 inches deep.

Tips

• Free magnetometer-based apps work on standard drywall but struggle with plaster or thick walls
• Calibrate the app on a known hollow section before scanning
• RF-accessory apps provide deeper and more reliable detection but require a compatible phone
• Confirm any app reading with a second method such as the nail-probe technique