Hidden apps, and the truth about codes like *#21# on iPhone
If you have seen a video telling you to dial a code to find out whether your phone is being watched, you are not gullible for trying it. Those videos get millions of views because the promise is exactly what a worried person wants: one quick check, and an answer.
We wish it worked like that. Here is what those codes actually do.
What *#21# really does
It shows you whether your calls are being unconditionally forwarded to another number. That is all.
It does not even cover every kind of forwarding. Forwarding that only kicks in when your phone is busy, switched off or unanswered uses different codes and will not show up here at all.
It is a standard code that talks to your phone network, not to your phone. It knows nothing about apps, nothing about software on your device, and nothing about whether anyone is monitoring you. Telecoms engineers and independent fact checkers have said so publicly.
That means a clear result tells you nothing reassuring. You can have a perfectly clean call forwarding result and still have a monitoring app running. And a forwarding entry is not proof of anything sinister on its own, because forwarding is a normal feature that people and telcos set up for ordinary reasons.
The same goes for the other codes that circulate. ##002# clears call forwarding. *#06# shows your phone's IMEI number. Neither is a monitoring check.
So the codes are not useless. They are answering a different question than the one you are asking. Call forwarding is worth a look. It is not a spyware test.
Apps that promise to detect spyware
Treat these with the same caution, and for the same reason.
Monitoring software that is any good is built to hide from exactly this kind of scan. An ordinary app on your phone cannot see the things it would need to see to give you a real answer. The reliable method is a forensic examination of the phone, which is normally done by police.
Most of the apps and websites making this promise are selling a subscription. We are not, because we have nothing to sell, which is the only reason we can afford to tell you this.
Using Android instead? Read the Android version of this page.
Before you change anything, please read this
If someone is monitoring you, the moment they lose that access is often the moment things get more dangerous. Family violence services see this pattern often enough that it shapes all of their advice.
So, three things before you touch a setting:
- Do not uninstall an app you suspect, and do not factory reset your phone, as your first move. It can tell the other person that you know.
- Removing it also removes the proof. If you might ever want to go to the police, that proof matters.
- Talk to someone first. 1800RESPECT is free, confidential and open 24 hours, on 1800 737 732. Call from a phone you trust, not from the one you are worried about.
None of this means you have to keep a phone you do not trust. It means the order matters, and the safest order starts with a plan and a person, not with a delete button.
One more thing worth knowing now. Talking about this near the phone can be enough. If monitoring software is running, it may be able to hear the room. Have this conversation somewhere else, or on another device.
What actually works better on an iPhone
Looking, carefully, with your own eyes. The good news is that an iPhone gives an app much less room to hide than other phones do.
See everything installed. Swipe left past your last home screen to the App Library. Apps can be removed from the home screen but still be installed, and they show up here.
Check for a management profile. This is the main one on iPhone. Settings, General, then VPN & Device Management. On a normal personal iPhone there is usually nothing here at all. A profile you did not add is worth more than any dial code.
Check for hidden apps under Screen Time. Settings, Screen Time, Content & Privacy Restrictions, Allowed Apps & Features. Apps switched off here disappear from the phone without being uninstalled.
Check your purchase and download history. In the App Store, tap your profile picture, then Purchased. Something installed that you did not install will usually be listed.
Run Safety Check. On iOS 16 and later, Settings, Privacy & Security, then Safety Check.
If you find something
Please do not delete it yet. We know that is the natural reaction.
Deleting it can tell the other person that you know, and it removes the proof. There is a safer order, and it starts with a conversation rather than a delete button. Please read the warning above, and then our page on what to do next.
What this page will not do
We will not tell you your phone is clean. Nobody honest can.
Monitoring software that is any good is built to hide, and the reliable way to find it is a forensic examination of the phone, usually done by police. Any website or app promising to scan your phone and give you a yes or no answer is overselling what it can do, and most of them are selling something. We are a not-for-profit and there is nothing to buy at the end of this.
Next: what to do, in a safe order
Where to get real help
- In immediate danger: call 000.
- 1800RESPECT: 1800 737 732. Free, confidential, 24 hours, by phone or online chat. For anyone affected by domestic, family or sexual violence.
- Police assistance line: 131 444, for threats to your safety that are not an emergency.
- WESNET Safety Net Australia: techsafety.org.au. Specialists in technology and family violence. If you use an Android phone and you think spyware may be on it, they ask people to contact them from a safe device.
- eSafety Commissioner: esafety.gov.au. The national regulator. It has legal powers to help with serious online abuse, including image-based abuse.