Is *#21# a hacker code? If you’ve just dialed *#21# because TikTok, Facebook, or YouTube told you it would expose a hacker, you’re definitely not the only one.
Every week, thousands of people search *“Is #21# a hacker code?” after watching viral videos claiming this simple code can expose hackers, spyware, or secret phone surveillance.
Then a phone number appears. Panic sets in.
“Whose number is that?”
“Is someone spying on me?”
“Has someone hacked my phone?”
Thankfully, the truth is much less dramatic.
No, *#21# is not a hacker detection code. It does not scan your phone for spyware, malware or hidden tracking apps.
On supported networks, it checks the status of a call-forwarding service. If a number appears, that doesn’t automatically mean someone has hacked your phone.
Let’s look at what the code actually does.
If you’re worried your phone may have been compromised, these are the 10 real signs your phone has been hacked that are worth checking.
What Does *#21# Mean?
*#21# is a service code used to check the status of certain call-forwarding settings on supported mobile networks. It is not a code that scans your phone for hackers or spyware.
The exact result can vary depending on your mobile carrier and phone. You may see a forwarding status, a phone number associated with a carrier service, or an error if the code isn’t supported.
To understand what *#21# does, forget about hackers for a moment.
Call forwarding is simply a service that allows incoming calls to be redirected somewhere else.
When you dial *#21#, your phone isn’t running a security scan. It is communicating with your mobile network to check the status of a specific call-forwarding setting.
That’s all.
So those viral videos claiming you can dial *#21# to discover whether someone is secretly spying on your phone are misleading.
The exact result you see can vary depending on your phone, mobile carrier and network.
Why Does *#21# Show a Phone Number?
This is usually the part that causes people to panic.
You dial the code, and instead of seeing something simple like “disabled,” a phone number appears.
But seeing a number does not automatically mean your calls are being secretly sent to a hacker.
Depending on your carrier, a number shown in the result may be associated with a carrier or voicemail service. However, the exact meaning of the result can vary by network, so don’t assume a particular number proves your calls are being intercepted or that it always means the same thing on every carrier.
If you’re unsure about a number shown in the results:
- Don’t panic.
- Check whether the number belongs to your mobile carrier or voicemail service.
- Contact your carrier if you still don’t recognise it or are concerned about your forwarding settings.
I wouldn’t recommend calling an unfamiliar number simply because it appeared after dialing *#21#.
Is *#21# Safe to Dial?
Yes. *#21# is generally safe to dial.
The code is used to check information about a call-forwarding service. It does not:
- Install anything on your phone
- Download spyware
- Share your personal information
- Give someone remote access to your device
- Hack your phone
If your carrier or network doesn’t support the code, you may simply receive an error message or a result that looks different from what you saw online.
Can Hackers Abuse Call Forwarding?
Technically, yes.
Call forwarding can be abused if someone gains access to your phone, SIM card, mobile account or another part of your communications setup and changes your settings without permission.
But that is very different from a random hacker somewhere simply typing your phone number into a computer and secretly taking control of your calls.
So, unauthorised call forwarding is something worth investigating if you discover a setting you didn’t enable. But seeing a number after dialling *#21# is not, by itself, proof that this has happened.
If you’re concerned about other ways someone could gain access to your phone, it’s more useful to understand how hackers can spy on your phone.
What *#21# Cannot Tell You About Phone Hacking
This is the most important thing to remember.
*#21# only checks one specific setting.
It cannot tell you whether:
- Spyware is installed on your phone
- Malware is running in the background
- Someone has stolen your passwords
- Your email account has been compromised
- Someone has access to your Apple or Google account
- A suspicious app is monitoring your activity
- Someone is reading your messages
So, even if your *#21# result looks completely normal, it doesn’t mean your phone has received a complete security check.
If you genuinely think something is wrong, look at the bigger picture.
Check for unfamiliar apps, unusual permissions, unexpected account activity and changes in how your phone behaves.
For a complete walkthrough, read Is My Phone Hacked? 10 Signs to Check Right Now.
What to Check If You Think Your Phone Has Been Hacked
Instead of relying on a single code, check for signs that point to a real security problem.
Look for:
- Apps you don’t remember installing
- Unusual battery drain or overheating
- Strange pop-ups or behaviour
- Unusual permissions given to apps
- Login alerts you didn’t expect
- Unknown devices connected to your Apple or Google account
- Messages or calls you didn’t make
One unusual sign doesn’t automatically mean your phone has been hacked. But several unexplained changes together are worth investigating.
Final Answer: Is *#21# a Hacker Code?
No. *#21# is not a hacker code.
It is a call-forwarding service code, not a tool for detecting spyware or hackers.
If a number appears after dialling it, don’t immediately assume that someone is spying on you. Check with your carrier if you’re unsure about the result.
And if you’re genuinely worried about phone security, don’t rely on one code. Check for the real signs your phone may have been hacked and investigate anything genuinely suspicious.
Depending on what you’re worried about:
- Someone spying on your phone? → Ways Hackers Spy on Your Phone
- Found something suspicious? → What to Do If Your Phone Is Hacked
- Want to check other viral codes? → Codes to Check If Your Phone Is Hacked
Interesting! I didn’t even know about the “21” code. Thanks for the tips and for sharing this helpful information.