Have you ever wanted to locate someone else’s mobile phone?
… if you have lost your own mobile phone or have been looking for your loved one.
This tutorial is the complete guide with all questions and answers about the legal situation and technology.
Let’s start!
The basics of tracking
Thanks to the Global Positioning System (GPS or NAVSTAR GPS), we can be located on the globe with an accuracy of a few metres. Satellite support and navigation systems enable us to reach our destination more quickly.
The predecessor was the Transit NNS, which has been used since 1958 to guide and navigate ballistic missiles, submarines and aircraft carriers. In the past, only the American military was allowed to use GPS.
Signals from space – The best frequencies
All satellites transmit on two frequencies with a data rate of 50 bits per second. Compared to a 25,000,000 bit DSL connection (25 Mbit), this is very lame.
- The L2 frequency (1227.60 MHz) is cleared for civilian purposes (navigation and positioning), which we are all allowed to use.
- The L1 frequency (1575.42 MHz) is used by the military and receives the following message content in 1500 bit messages every 30 seconds:
- Satellite identifier
- Current date
- Identification number
- Corrections of the satellite
- Orbits of the satellite
- Status of the satellite
Positioning explained simply
To determine your exact location, your mobile phone needs a radio connection to at least three satellites. Your navigation device measures the distance (approx. 20,200 km) to the satellite with the time span between satellite time and earth time.
Determining speed with the Doppler effect
Smartphones measure the speed of a vehicle or person based on the Doppler effect. The Doppler effect is a physical phenomenon:
Doppler effect: when you move fast in one direction, you compress your sound waves in front of you (higher sound), while the sound waves behind you are stretched (lower sound).
Steffen Lippke
Example: When an ambulance coach passes you, the pitch of the signal tone changes significantly from high to low.
A few mathematical formulas combined with GPS determine the speed, direction and location of the device.
A very precise atomic clock accurately measures the time in the satellite to avoid a locating error.
Common questions
Can you locate a mobile phone?
You can locate a mobile phone not only through GPS. The phone number is another indicator. Mobile phone providers are only allowed to sell SIM cards if the person identifies themselves. Mobile phone tracking with a number or mobile phone number can be done by the mobile phone provider via Telekom. I have described in detail how to do this in the guide Locating a Mobile Phone in 7 Ways. Behind “free” online tools, you will only find scammers who claim false facts.
How can I locate a mobile phone when it is off?
A mobile phone that is switched off properly is not really off, but is in a sleep state with a black screen. You can wake up the phone and turn on tracking via a SIM rootkit. Then you can use the GPS as usual. This method does not work if the phone is deeply discharged. A 2 – 3 % battery may still be enough because the phone does not need to turn on the screen to give a signal.
If your smartphone is only locked (i.e. the screen is black and can be started with one press), your device is active despite the snooze state. You can locate the device via GPS, UMTS or Bluetooth.
Locating a mobile phone with a WhatsApp number?
WhatsApp is an application from Meta (formerly Facebook). Since 2020, 530 million data records with mobile phone number, email and home address have been floating around on the internet. You can read the location data of the people in the dataset. I explain other techniques in the WhatsApp hacking and Instagram hacking guide.
Can I track my smartphone, bike, car, wallet, etc.?
You are allowed to track your property as long as you don’t try to track someone else with it, e.g. put your own smartphone in your wife’s pocket.
Tracking is handy if you can’t find your car in the city or want to look for your bike in the dark. You can buy the little trackers for spot prices at Chinese online stores, but don‘t install malware on your devices. Apple Air Tags are just a hip remake of technology that has been around for years.
Locate your phone for Android, iOS, Windows Phone
Before you try to locate your device for theft, you should call your mobile operator and have your SIM card blocked. Get the other person’s consent if you want to track them.
How can I locate another mobile phone for free?
iOS / Apple: You can find Apple devices using the “Where is” feature. This app is installed on every device by default. Other third-party apps from the App Store use the classic GPS. This must be activated all the time. “Where is” works with Bluetooth pulses emitted by any Apple device.
Activate the app in Settings > Account > Where Is > Share Location. Normally, this option is on when you have connected the phone to an Apple account.
You should also enable location services.
Settings > Privacy > Location Services
Go to the Apple website of Where’s https://www.apple.com/de/icloud/find-my/ and log in with the account. Alternatively, use the Apple app from another device (same account).
Android: Activate “Security”>”Device Security”>”Security & Location” on your Android phone. In Google Device Manager you can track the location history of your device. Then log in to your Google Account and go to the “Devices” page. There you can track the location live.
Make sure the following setting is on in your phone. Normally this setting is on if you have set up a Google Account.
Settings > Security > Find My Device > On
If this option is activated, you can use your Android iPhone with the website https://android.com/find or with the app “Find My Device” / Google Find MyDevice.
In the application, you then have several options when you locate the phone:
- Play sound –> Maybe you will find it easier in the bush / the thief’s pocket that way
- Secure Device –> No one can access the data. Password guessing is unsuccessful
- Erase Device –> Erase all local data remotely.
Windows Phone: If you use a Windows Phone, you have to activate the tracking in the settings. You can find your device on the windowsphone.com website. You should also find other tracking apps in the Windows Store.
Which devices can I locate?
- Smartphones / mobile phones
- Smartwatches / better fitness trackers
- Any button phone (via mobile)
- Devices with a connection to the internet
- Newer cars
- etc.
Top tip: Alternative GPS sensor
In addition to smartphones, the market offers special GPS sensors that use a rechargeable battery. Instead of ordering an expensive tracker (50 – 200 dollar) on the well-known German e-shopping platforms, buy a GPS tracker from Chinese competitors.
The devices are much cheaper (from 30 dollar).
Ingenious additional function Tips for tracking
You can use the platforms of the various mobile phone manufacturers to..
- Lock completely
- Display a hint
- Output a sound signal
Your mobile phone is not a work tool on which private or business data should be permanently stored. Use a secure cloud, device encryption and remote wipe!
Steffen Lippke
How can I locate my iPhone?
Apple developed the Where Is feature. When activated, your device sends out Bluetooth signals to random Apple devices at regular intervals.
If you lose your Apple device, or it is stolen, you can have your device located without GPS or Wi-Fi if a stranger with an Apple device is nearby.
The unfamiliar Apple device uploads encrypted Bluetooth signals from your device to the Apple Cloud. The owner of the foreign Apple device does not notice anything. Apple claims the system is fully encrypted and securely built, but that’s only half the truth – behavioural data analysis.
With your second Apple device and the same encryption (private key), you can decrypt the location data packets of your device in the iCloud.
If the thief is a bit more intelligent, he wraps the device in many layers of aluminium foil (Faraday cage) and the device is gone forever.
Law – Who is allowed to track whom and when?
For the layman, the legal texts are a big pile of rules, norms and penalties.
Who is allowed to locate whom and when?
Steffen Lippke
Here is an overview of what the law says.
Am I allowed to locate a stranger?
Technically, it is easy to locate a device with GPS, mobile radio, Bluetooth or W-LAN. Legally, it’s a bit more complex. To locate a person using a mobile phone or GPS sensor, you need written consent from the person.
Location is one of the personal data protected by the GDPR. With just two locations of a random smartphone, an algorithm can determine who owns the device:
If you locate the smartphone at 11 a.m. and 3 p.m., you can most likely map the person’s place of residence and workplace.
Steffen Lippke
You determine the name of the owner with these two locations and a Google search. The power of Big Data can be terrifying.
When are the police allowed to locate me?
The German police are allowed to locate you if they have a legitimate interest (e.g. suspicion of a serious crime). The police and the BKA sent 310,000 silent text messages to locate people in 2013. The police and the BKA send silent text messages to locate and arrest people in real time. Locating people with the help of radio masts does not allow exact positioning, but limits their whereabouts to a larger radius. 400 silent text messages are needed on average by the police to make an arrest (2019: 112,354, 2018: 111,628)
How can you find out someone’s location?
Any tracking of a mobile phone needs notification and consent by SMS in advance. However, you are allowed to locate your own devices in use. Courts do not logically allow you to attach your own device to the other person’s car. For other people’s devices, you need the written consent of the person to be tracked.
Location is personal data that needs to be protected. Parents are allowed to track their young children. With teenagers, personal rights come to the foreground and tracking is no longer legal. Even if the parents pay for the teenager’s smartphone and /or contract, the child has a right to privacy under the law.
Not being trackable – what to do?
Tracking is good and bad at the same time. This section explains how you can protect yourself against tracking.
Hardware protection against tracking / silent SMS
Several layers of aluminium foil or a special Faraday cage mobile phone case can help against tracking. Contrary to the opinion of many, such a bag is not guaranteed to be safe against RFID attacks, because even chips can be read through thick steel.
Note that such protection blocks any radiation. If you are called, your mobile phone will not receive anything. Alternatively, the police can locate you with the radio masts without you having to have your GPS switched on.
Steffen Lippke
Convenience (online, telephone, internet services) and security (2-factor authentication, privacy) are mutually exclusive to a certain extent.
