Your Android phone has a surprising number of tools hidden beneath the surface. While most people rely on the Settings app for everything, the Android dialer can also act as a gateway to diagnostic menus, hardware tests, network information, and other system details.

These commands are commonly known as Android secret codes, Android dialer codes, or USSD/MMI codes, depending on how they work. Some display information such as your IMEI number or firmware version. Others can open hardware testing menus for the touchscreen, speakers, sensors, battery, Wi-Fi, and cellular radio.

The catch? There is no single universal list that works on every Android phone.

Samsung, Google Pixel, Motorola, Xiaomi, OnePlus, OPPO, and other manufacturers can enable, modify, or completely disable different codes. Android updates can also make older codes stop working.

So before entering random combinations into your dialer, here’s what you need to know about Android secret codes, which ones are generally useful, which ones require caution, and what to do when a code doesn’t work.

What Are Android Secret Codes?

Android secret codes are special character-and-number sequences that can trigger hidden functions in the phone’s software.

Many were originally intended for phone manufacturers, engineers, carriers, and repair technicians. They provide a fast way to inspect hardware, check firmware, troubleshoot connectivity, and access engineering or diagnostic information without navigating through numerous menus.

For example, entering:

*#06#

usually displays your phone’s IMEI number immediately.

Other codes can open testing interfaces containing information about cellular networks, Wi-Fi, battery statistics, sensors, or hardware components.

Some commands are relatively harmless because they only display information. Others can modify configuration settings, activate diagnostic functions, or perform a factory reset.

That’s why you should never assume that every code you find online is safe.

How Do Android Secret Codes Work?

When you type a supported code into the phone’s dialer, Android or the device manufacturer checks whether that particular command is recognized by the phone’s telephony or system software.

If it is supported, the corresponding function can launch automatically.

Some codes use the familiar *#*#...#*#* format. These are often called Android MMI secret codes or USSD-like codes, although technically the underlying mechanisms can differ.

Other commands are carrier or manufacturer codes and may require you to press the Call button.

The important thing is that Android doesn’t have one universal secret-code system covering every device.

A code that works on a Samsung Galaxy may do nothing on a Google Pixel. A command that worked on Android 10 may also have been disabled in a later firmware update.

Why does *#*#4636#*#* sometimes not work?

One of the most frequently mentioned Android codes is:

*#*#4636#*#*

On compatible devices, it can open an Android testing menu containing information about the phone, network, Wi-Fi, and other system statistics.

However, it is not guaranteed to work on modern Android phones.

Manufacturers can remove or restrict access to the menu, and newer firmware versions may handle the command differently. Samsung, in particular, has restricted access to several traditional Android testing codes on newer Galaxy software.

So if *#*#4636#*#* doesn’t work, that does not necessarily mean you entered it incorrectly.

Are Android Secret Codes Safe?

Some are. Some aren’t.

The safest codes are generally those that only display information. For example, checking an IMEI number doesn’t normally modify anything on the phone.

Diagnostic codes can also be useful because they simply launch a test screen.

However, certain service, configuration, and reset commands can make changes to your device.

A factory-reset command is obviously much more dangerous than a code that displays your firmware version.

Follow these precautions before trying a code

1. Know what the code does first.
Never enter an unfamiliar command simply because someone described it as a “hidden Android trick.”

2. Back up important data.
If you’re testing a command that can modify or erase data, create a backup first.

3. Be particularly careful with reset codes.
Commands associated with factory resets or firmware operations can potentially erase personal data.

4. Don’t change engineering settings unless you know what they control.
Radio bands, modem configuration, USB modes, and other engineering settings can affect connectivity or device behavior.

5. Don’t assume a code is universal.
A code documented for one phone model may have a completely different behavior—or no behavior at all—on another.

6. Stop if a destructive option appears.
If a menu displays a reset, wipe, format, or firmware option you weren’t expecting, exit instead of experimenting.

Important: Secret-code behavior varies by manufacturer, model, carrier, chipset, and Android version. The tables below should be treated as a reference, not a guarantee that every code will work on your phone.

How to Use Android Secret Codes

Trying a supported Android dialer code is usually straightforward.

1. Open the default Phone or Dialer app on your Android device.
2. Enter the code exactly as written.
3. If the code is designed to execute automatically, wait for the corresponding menu or information screen.
4. If the command requires it, press the Call button.
5. Read the information or perform the diagnostic test.
6. Exit the menu when you’re finished.

Some codes will appear to do nothing because your manufacturer has disabled them.

Use the default dialer when possible

Third-party dialer applications may not support every type of Android service or diagnostic code.

If a code doesn’t work, try the phone’s original dialer before assuming the command is unsupported.

Best Android Secret Codes to Try

The following list focuses on commonly documented Android and manufacturer codes.

Because support changes between devices, don’t treat a code’s presence in this table as proof that it works on your specific phone.

Android Codes for Device Information

These are among the most useful codes because they can reveal information about your phone without requiring you to navigate through multiple settings menus.

The most useful code: *#06#

If you only remember one Android secret code, make it:

*#06#

It is widely supported and provides your phone’s IMEI information.

You may need your IMEI when contacting a carrier, checking device records, or identifying a particular cellular device.

Don’t publicly post your IMEI online. It is device-specific information and should be treated as private.

Android Codes for Battery and System Diagnostics

Battery information is one of the most common reasons people search for Android secret codes.

Unfortunately, there isn’t one universal dialer code that provides a complete and reliable battery health percentage on every modern Android phone.

On compatible devices, however, some codes can expose battery voltage, temperature, charging information, or other diagnostic readings.

Can secret codes show battery health?

Sometimes, but not reliably across all Android phones.

Modern devices increasingly provide battery health information through their normal Settings apps, manufacturer diagnostics, or dedicated support tools.

For example, a code that once exposed detailed battery information on an older Android build may simply be ignored by a newer phone.

If you’re trying to determine whether your battery needs replacement, use the manufacturer’s official battery diagnostic tools whenever available.

Android Hardware Test Codes

Secret codes can also be useful when troubleshooting physical hardware.

If your touchscreen isn’t responding correctly, a speaker sounds distorted, or a sensor appears broken, a diagnostic menu may help determine whether the problem is software-related or hardware-related.

Testing a touchscreen

If you’re buying a used Android phone, touchscreen testing can be particularly useful.

A diagnostic test may allow you to touch or draw across the entire screen. Watch for areas where touch input consistently fails.

That can help reveal:

• Dead zones
• Unresponsive areas
• Inaccurate touch registration
• Multi-touch problems
• Intermittent touch failures

If the code doesn’t work, don’t assume the display is faulty. Your phone may simply not support that particular diagnostic command.

Android Wi-Fi, Bluetooth, GPS, and Network Codes

Network-related codes are another popular category.

They can provide information about the cellular radio, Wi-Fi hardware, Bluetooth interface, or GPS system.

Be careful with network engineering menus

Some Android service codes do more than display information.

Engineering menus can expose options related to:

• Cellular bands
• Modem configuration
• Radio diagnostics
• USB modes
• Network logging
• Carrier settings

Changing the wrong option can cause connectivity problems.

If you’re simply trying to troubleshoot weak cellular reception, view diagnostic information rather than changing radio settings unless you know exactly what you’re modifying.

Android Call and Carrier Codes

Some dialer codes aren’t manufacturer-specific diagnostic commands at all.

They’re standardized telephony commands used for services such as call forwarding and call waiting.

Availability can still depend on your carrier and network.

Why these codes may behave differently

Unlike purely local diagnostic codes, carrier commands interact with your mobile network.

That means the result can depend on:

• Your carrier
• Your country
• Your SIM
• Your mobile plan
• Your network technology
• Carrier-specific restrictions

A command that works on AT&T, Verizon, or T-Mobile may not behave identically on another network.

Android Developer and Debug Codes

Some codes open interfaces originally designed for engineers and service technicians.

These are not recommended for casual experimentation.

A diagnostic screen that only displays information is one thing. A service menu containing configuration controls is another.

If you don’t know what an option does, leave it unchanged.

Factory Reset and Other Dangerous Android Codes

This is the category where you should be especially careful.

Older Android code lists frequently circulate commands that can trigger factory resets or other destructive operations.

Examples include:

Do not test destructive codes on your primary phone.

Their behavior is heavily dependent on firmware, and old code lists can be inaccurate for modern devices.

If you need to factory-reset an Android phone, use the official Settings > System > Reset options process instead. It is considerably easier to understand and gives you a clearer indication of what will happen.

Samsung Secret Codes

Samsung Galaxy phones have their own collection of diagnostic and service codes.

Some are particularly useful when checking a used Galaxy phone or troubleshooting hardware.

Samsung and the 4636 code

One of the most common misconceptions is that every Samsung phone should open the Android testing menu when you enter:

*#*#4636#*#*

That’s not true.

Samsung has its own diagnostic framework, and modern Galaxy devices can restrict or disable certain generic Android codes.

If you’re using a recent Galaxy phone, Samsung’s own diagnostic tools are generally more relevant than relying on old lists of universal Android codes.

Motorola Secret Codes

Motorola devices have historically used their own service and diagnostic commands.

One commonly documented command is:

##7764726

It can open a service-programming interface on certain Motorola devices.

However, Motorola’s software has changed considerably over the years, so support depends heavily on the model and firmware.

Don’t modify service-programming values unless you’re specifically following an official repair procedure.

Xiaomi and Redmi Secret Codes

Xiaomi and Redmi phones can expose hardware testing menus through manufacturer- and chipset-specific commands.

Commonly documented examples include:

*#*#6484#*#*

and, on some MediaTek-based devices:

*#*#3646633#*#*

These may provide access to hardware diagnostics involving sensors, speakers, cameras, vibration, connectivity, and other components.

However, MIUI/HyperOS versions and individual models can differ substantially.

If a Xiaomi or Redmi code does not work, use the device’s built-in hardware test or diagnostic features instead of repeatedly trying unrelated engineering commands.

OnePlus Secret Codes

OnePlus phones have used various engineering and diagnostic menus across different generations.

A commonly referenced command is:

*#800#

On supported models, it can open a feedback, log, or engineering interface.

Because OnePlus has changed its software architecture across OxygenOS generations, the exact behavior isn’t guaranteed.

Always verify the code against your specific model and OxygenOS version before using engineering features.

Huawei and Honor Secret Codes

Huawei devices have historically included an engineering mode accessible through:

##2846579##

On compatible phones, this can expose manufacturer service and testing functions.

Again, availability varies by model and software version.

Do not change network, radio, or calibration settings unless you are performing a documented service procedure.

OPPO, Realme, and Vivo Secret Codes

OPPO, Realme, and Vivo phones can also include manufacturer-specific engineering menus.

Commonly reported commands include:

*#808#

and, on some MediaTek-powered devices:

*#*#3646633#*#*

These menus can provide hardware tests and engineering information.

The exact functions vary by model, chipset, region, and software version, so a code that works on one Realme phone may not work on another.

Google Pixel Secret Codes

Google Pixel phones are somewhat different from many manufacturer-customized Android devices.

The generic Android testing code:

*#*#4636#*#*

may work on some Pixel builds, but Google has increasingly relied on standard Android settings, diagnostics, Developer Options, and ADB for advanced troubleshooting.

For deeper Pixel troubleshooting, built-in diagnostic features and Google’s official support tools are generally more dependable than old secret-code lists found online.

Useful Android Backup and Utility Codes

Some older Android devices also support codes associated with backup, calendar information, Google Play Services, and debugging.

These commands are particularly dependent on Android version and manufacturer software.

What to Do If an Android Secret Code Doesn’t Work

Don’t immediately assume you’ve typed the code incorrectly.

There are several reasons why an Android dialer code may fail.

1. Your manufacturer disabled it

This is one of the most common explanations.

Samsung, Google, Xiaomi, OnePlus, and other manufacturers can remove access to engineering commands.

2. Your Android version changed

A code that worked on Android 9 or Android 10 may no longer work on a newer release.

Security improvements have led manufacturers to restrict access to some low-level functions.

3. Your phone uses a different firmware version

Even two phones with the same model name can behave differently depending on:

• Region
• Carrier
• Firmware
• Android version
• Chipset
• Bootloader configuration

4. Your carrier restricts the command

This is especially relevant for network and call-management codes.

5. You’re using a third-party dialer

Some commands require the manufacturer’s default Phone application.

6. The code is simply outdated

This is a major problem with secret-code lists published online.

Many lists copy codes from old Android phones without checking whether they still work on current devices.

How to Troubleshoot a Secret Code That Won’t Run

If a code doesn’t respond, try these steps:

1. Confirm the code carefully. One missing * or # can make the command invalid.
2. Use the default Phone app.
3. Restart your phone.
4. Install available Android and security updates.
5. Check whether the code is specifically intended for your manufacturer.
6. Try your manufacturer’s official diagnostic tools.
7. Don’t randomly experiment with similar-looking codes.

You generally don’t need an internet connection for local diagnostic codes.

However, carrier commands such as call forwarding or call waiting can require an active cellular connection and may be handled directly by the network.

Are Android Secret Codes the Same as USSD Codes?

Not exactly.

The terms are often used interchangeably online, but they refer to different mechanisms.

USSD codes generally communicate with your mobile network. They’re commonly used for carrier services, account information, and network functions.

Android secret codes usually trigger functions handled by the phone itself or its manufacturer software.

There is also MMI (Man-Machine Interface) syntax, which is used by cellular devices for certain service commands.

That’s why an article may call all of these “secret codes” even though they don’t all operate in exactly the same way.

Can Android Secret Codes Unlock Hidden Features?

Sometimes.

They can reveal information and diagnostic tools that aren’t visible in the normal Settings interface.

However, secret codes generally don’t magically unlock premium features, increase CPU performance, improve camera quality, or bypass Android security.

Be especially skeptical of websites claiming that a secret code can:

• Give you free mobile data
• Increase your internet speed dramatically
• Unlock paid features
• Bypass a Google account
• Remove a carrier lock instantly
• Increase battery capacity
• Double your phone’s RAM

Those claims are often misleading.

Can Secret Codes Improve Android Performance?

Generally, no.

Secret codes can help you diagnose performance problems, but they aren’t magic performance boosters.

For example, diagnostic information might help identify:

• Battery overheating
• Abnormal battery voltage
• Network problems
• Faulty sensors
• Hardware failures
• Firmware information

But changing hidden engineering settings simply because you found them online can actually create new problems.

For improving Android performance, you’re usually better off managing storage, updating the operating system, removing unnecessary applications, checking battery usage, and troubleshooting the specific problem.

Are Android Secret Codes Still Useful in 2026?

Yes—but their usefulness has changed.

Older Android phones exposed many more engineering functions through the dialer. Modern Android devices increasingly restrict low-level access for security and reliability reasons.

As a result, today’s most useful codes tend to be simple diagnostic or identification commands rather than powerful configuration shortcuts.

The IMEI code *#06# remains one of the most useful examples.

For hardware diagnostics, manufacturer-specific tools are increasingly replacing traditional dialer codes.

This is especially true for newer Samsung Galaxy, Google Pixel, Xiaomi, and other flagship devices.

Final Thoughts

Android secret codes can give you a fascinating look beneath the surface of your smartphone.

With the right command, you can check an IMEI number, inspect firmware information, test a touchscreen, examine sensors, troubleshoot wireless hardware, or access diagnostic information that isn’t normally visible in Android’s Settings app.

But there’s an important catch: Android secret codes are not universal.

A command can work perfectly on one phone and do absolutely nothing on another. Android updates, manufacturer software, carrier restrictions, regional firmware, and chipset differences can all affect compatibility.

For that reason, start with information-only codes such as *#06#, and treat engineering, configuration, and reset commands with much more caution.

The best approach isn’t to try every secret code you can find. It’s to identify the specific problem you’re trying to solve, use a code designed for that purpose, and avoid changing settings you don’t understand.

Used carefully, these hidden Android commands can turn your phone into a surprisingly useful diagnostic tool—without installing another app.

Frequently Asked Questions

What is the most useful Android secret code?

*#06# is one of the most useful and widely supported codes because it displays your phone’s IMEI information. Other diagnostic codes vary considerably by manufacturer and Android version.

Does *#*#4636#*#* still work?

It works on some Android devices, but many newer phones restrict or disable the testing menu. If nothing happens, your device’s firmware likely doesn’t support the command.

How can I check Android battery health with a secret code?

There is no universal battery-health code that works reliably across all Android phones. Some devices expose battery voltage, temperature, or status through diagnostic codes such as *#0228#, while newer phones may provide battery information through their Settings or manufacturer diagnostics.

Can Android secret codes damage my phone?

Information-only codes are generally low-risk, but engineering and reset commands can change system configuration or erase data. Never use an unfamiliar reset or firmware command without first understanding exactly what it does.

Do Android secret codes work on Samsung Galaxy phones?

Some do, but Samsung uses many of its own diagnostic commands and restricts several generic Android codes on newer Galaxy software. Codes such as *#0*# can open Samsung’s hardware test menu on supported models.

Do Android secret codes work on Google Pixel phones?

Some standard Android commands may work on Pixel devices, but support depends on the Android build. Google also provides built-in diagnostic and troubleshooting tools that can be more reliable than older secret-code lists.

Do I need the internet to use Android secret codes?

Most device-level diagnostic codes work without an internet connection. Network and carrier commands, however, may require an active SIM and cellular connection because they communicate with your carrier’s network.

Can secret codes unlock a carrier-locked Android phone?

No. A random Android secret code should not be expected to legitimately bypass a carrier lock. Carrier unlocking normally requires the carrier’s authorization and an eligible device.

Can I create my own Android secret codes?

No. You cannot invent a working secret code for your phone. The command must already be implemented by Android, the manufacturer, the carrier, or the device’s firmware.