If you have ever wondered whether someone can read your WhatsApp messages or watch what you do on your phone, this guide shows you how to check properly. Most “signs of spyware” lists online are guesswork. The checks below look at the places monitoring actually shows up.
Quick answer
Open WhatsApp and check Linked Devices. Every device currently able to read your chats is listed there, and you can log any of them out immediately.
Then check your phone for apps with device admin or accessibility access on Android, or an unexpected configuration profile on iPhone. Those are the three places monitoring hides.
Read this first: if you think someone monitoring you may become angry or dangerous, do not remove anything yet. Removing monitoring software tells that person you found it. Consider using a different, safe device first and contacting a local domestic abuse support service before you change anything.
On this page
Signs that people worry about but do not actually prove much
Almost every article on this topic lists battery drain, a warm phone, higher data use, and random restarts. These are worth knowing about, but on their own they prove nothing. Modern phones show all of these symptoms for completely ordinary reasons: an aging battery, a heavy app update, a bad mobile signal making the radio work harder, or a background sync that got stuck.
Treat them as a reason to run the real checks below, never as proof by themselves.
Weak signals
Battery drain, heat, data spikes, slow performance, random restarts. Common on any older phone.
Strong signals
An unknown linked device, an app you did not install holding admin or accessibility access, or a profile you did not add.
Check 1: who is currently reading your WhatsApp
This is the single most useful check, and most people have never opened the screen. WhatsApp lets your account be linked to companion devices, such as a computer browser or a desktop app. Anything linked this way can read your conversations.
Open WhatsApp, go to Settings, then Linked Devices. You will see every device currently linked to your account, along with when it was last active. If you see something you do not recognise, tap it and log it out. That access ends immediately.
Tip: Do this check first. It is fast, it needs no technical knowledge, and it covers the most common real-world case, which is someone linking your account to their own computer while holding your unlocked phone.
Then turn on two-step verification in WhatsApp settings. It sets a PIN that is required before your number can be registered on a new device, which blocks the other common route: someone moving your number to their phone. WhatsApp documents the steps separately for Android and iPhone.
Official source: WhatsApp keeps its own safety and security help pages, which are the place to confirm current steps if a menu on your phone does not match what you see here.
Check 2: Android, the two permissions spyware needs
Monitoring apps on Android almost always need one of two powerful permissions, because there is no other way to read what happens inside other apps. Both are visible if you know where to look.
Device admin apps
In Settings, look under Security for device admin apps. This permission makes an app hard to uninstall. Very few normal apps need it.
Accessibility services
In Settings, open Accessibility and review which apps have access. Accessibility can read screen content, so monitoring tools abuse it constantly.
Run Play Protect
Open the Play Store, tap your profile picture, then Play Protect, and scan. It now flags many commercial monitoring apps.
Read the full app list
Not the home screen, the full list in Settings, since monitoring apps hide their icon. Look for bland names like “System Service” or “Device Health”.
Note: Menu names move between Android versions and phone brands. If a path here does not match your phone, search the exact wording in your Settings search bar.
Check 3: iPhone, where it is different
Installing hidden monitoring software on a normal, up to date iPhone is genuinely hard. iOS does not let an app quietly read other apps. That is real protection, and it means the honest answer for most iPhone users is that a secret spy app is unlikely.
The realistic iPhone risks are different, and they do not involve installing anything on your phone at all:
Risk 1
Someone knows your Apple ID
They can see backups, photos, and location without touching your phone.
Risk 2
A configuration profile
Under Settings, General, in the device management section. Remove any you did not add.
Risk 3
Location sharing left on
Check Find My and Family Sharing for people you forgot about.
Also open your Apple ID settings and scroll to the device list. Every device signed into your account appears there, and you can remove any that should not be. Do the same for your Google account if you use Android.
On iPhone, the account is usually the way in, not the phone itself.
What to do if you find something
In this order
✓ Think about safety before you remove anything.
✓ Change your account passwords from a different, trusted device.
✓ Turn on two-factor authentication everywhere it is offered.
✓ Log out unknown linked devices and sessions.
✓ Change your phone passcode, and do not reuse an old one.
A factory reset removes almost everything, but only do it after your accounts are secured. Otherwise the same person can simply sign back in and restore access.
Keeping it from happening again
Nearly every real case of phone monitoring starts the same way: somebody had physical access to an unlocked phone for a few minutes. Not sophisticated hacking, just an unlocked device left on a table.
A strong passcode that nobody else knows, two-factor authentication on your main accounts, and an occasional look at your linked devices will prevent the overwhelming majority of this. Our smartphone security guide covers the rest of the basics, including lock screen settings and safer backups.
It is also worth thinking about what you hand over voluntarily. Apps and online services collect far more than most people expect, and the same habit of checking permissions applies there too. If you use AI apps, what those tools do with your data is worth understanding before you paste anything personal into them.
Key takeaway: Check linked devices, check what has admin or accessibility access, secure the account rather than only the phone.
Not sure what an app is allowed to access?
Run it through our free App Permission Risk Checker and see what its permissions actually allow in plain language.
Can someone read my WhatsApp messages without my phone?
Yes, in two ways. They can link your account to their own device through Linked Devices, which requires brief physical access to your unlocked phone, or they can register your number on their device if they can receive your verification code. Turning on two-step verification blocks the second route, and checking Linked Devices reveals the first.
Does a battery draining fast mean I have spyware?
On its own, no. Battery drain is far more often caused by an aging battery, a recent update, or a weak mobile signal. Treat it as a reason to run a proper check rather than as proof of monitoring.
Can spyware be installed on an iPhone?
It is much harder than on Android because iOS does not let one app quietly read another. The realistic iPhone risk is account based: someone who knows your Apple ID can see backups, photos, and location without installing anything on the device.
Will a factory reset remove monitoring software?
It removes almost everything on the device, but it does not help if the other person still knows your account passwords, because they can sign back in. Secure your accounts from a different trusted device first, then reset.
Is it legal to monitor someone else’s phone?
Monitoring an adult without their knowledge or consent is illegal in many countries and is treated as a serious offence in some. This guide is written to help you find out whether you are being monitored, not to help anyone monitor another person.
