Slide your phone across the wall and Stud Finder reveals what's hiding underneath. No more drilling blind.
HOW IT WORKS
How a stud finder app works on iPhone
Stud Finder is a free iOS app that locates wall studs using the iPhone's built-in magnetometer, replacing $20–$50 hardware stud finders for DIY tasks like mounting TVs, shelves, and cabinets. The magnetometer is the same three-axis sensor the Compass app uses; the app watches for magnetic spikes from the screws and nails that anchor drywall to each wall stud, then shows you where to drill.
The sensor you already have
Every iPhone from the iPhone 5 onwards ships with a three-axis magnetometer. Apple uses it for the compass and for augmented-reality heading. We repurpose that same chip to measure tiny magnetic disturbances in a drywall surface — the ones created by the steel screws and nails driven into the studs.
A standard wall has a stud every 16 inches (or sometimes 24 inches). Each stud is anchored to the drywall with several fasteners. The app does not detect the wood itself; it detects those fasteners. Because the fasteners sit within an inch of the stud's center, finding them is close enough to mount safely.
HOW IT WORKS
A real-time magnetic reading shows you exactly how strong the signal is. Higher numbers mean a screw or nail is right there.
Fine-tune the Stud Finder sensitivity for any surface. Drywall, plaster or brick all get an accurate reading.
Track magnetism on all three axes at the same time. You see exactly which direction the metal is pulling from.
Tips for an accurate reading
- Hold the iPhone flat against the wall. Even half an inch of air gap weakens the signal.
- Sweep slowly — no faster than a few inches per second.
- Scan from both directions and mark where the peaks line up. The center of the two marks is the stud.
- Remove MagSafe wallets, magnetic cases, and metal kickstands. They confuse the reading.
- If the wall seems dead, try a spot near an outlet box. Outlets are almost always mounted directly to a stud.
When a stud finder app is the right tool
For hanging pictures, shelves, curtain rods, and most flat-screen TVs on standard drywall, a phone-based stud finder app is reliable, free, and always with you. For very heavy mounts, plaster walls with metal lath, or commercial steel-stud construction, combine the app with a hardware capacitive stud finder and drill only where both agree.
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See behind the wall,
now in your pocket.
Stud Finder turns your phone into a precision wall scanner. Know where the studs, screws and pipes are before you drill.
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