Stud Finder
1. Check your exact phone, not just its brand
Android devices do not all have the same sensors. A magnetometer measures magnetic field strength along three axes; a phone without that hardware cannot gain it by installing an app. Android provides a way for apps to check whether a sensor is available.[1]
Open Stud Finder and run its compatibility check before subscribing. A working compass can be a clue, but a compass that fails may also have a calibration or software problem. The in-app hardware check is more useful than assuming every model from a particular brand has the sensor.
Stud Finder is available for Android. There is no iPhone version of this product; that is a product availability statement, not a claim that iPhones cannot read magnetic sensors.
2. Decide whether magnetic detection fits your wall
On drywall attached to wood studs, a repeatable magnetic response may come from a steel screw or nail. Other steel objects can produce a response too. Several local responses aligned vertically are more useful than one isolated hit, but they still do not measure the edges of the wood.
Plaster over wood lath may contain detectable nails, but their depth can make detection unreliable. Plaster over metal wire lath produces a different, broader pattern. See the guide to wood lath versus wire lath before treating the two as the same wall.
If you need to establish stud edges or verify a heavy mounting point, compare magnetic and electronic tools and follow the mounting hardware manufacturer's instructions.
3. Make a repeatable scan
- Check the sensor. Run the compatibility check and follow any calibration prompts in the app.
- Remove magnetic accessories. Take off cases with magnets or metal plates, and move away from loose metal objects.
- Scan a small area slowly. Keep the phone's position and distance from the wall consistent. Repeat the pass from the other direction.
- Mark repeatable responses. A hit should occur in the same place on successive passes. Do not interpret a particular microtesla number as a universal stud threshold.
- Compare above and below. Look for separate responses along a vertical line. If the result is broad, inconsistent, or absent, use another method rather than guessing.
A magnetic response cannot establish load capacity or rule out wires and pipes. Finding fasteners and choosing a safe mounting method are separate tasks.
What is free, and what requires a subscription?
The magnetometer compatibility check is free. The site lists scanning at $4.99 per week with a 3-day trial, or $39.99 per year. Check the price, trial eligibility, and renewal terms shown in Google Play before subscribing. A hardware check confirms the presence of a sensor; it does not prove that your wall can be scanned successfully.
Can this website scan the wall?
This website is a guide and download page; it does not perform a magnetic scan. Some browsers expose a Magnetometer API, but support and permissions vary.[2] Stud Finder uses its Android app for scanning.
If your phone cannot find a repeatable signal
Stop and check the wall type, sensor location, and distance from the fasteners. Lack of a signal does not prove that a wall has no studs. A dedicated detector or another verification method may be needed. See what a phone stud finder can and cannot demonstrate for help interpreting the result.