Introduction: What is *#0*# in Samsung Phones?
Samsung smartphones are packed with hidden tools meant for testing hardware. Among these, one of the most powerful and secret tools is the diagnostic code *#0*#. Samsung engineers rely on this diagnostic tool for factory testing.
*#0*# is Samsung’s most powerful diagnostic tool, unlocking a hidden menu to test your phone’s hardware — from screen and camera to sensors and speakers. In this guide, you’ll learn how to use *#0*# in 2025, what it does, and which devices support it.
By simply dialing *#0*# on your phone’s keypad, you can access a deep diagnostic menu that allows you to test:
- Screen colors
- Touch sensors
- Camera modules
- Vibration motors
- Sensors like accelerometer and gyroscope
- Speakers and more
Originally designed for technicians, this code has become a valuable trick for regular users who want to check if their phone is working properly — without downloading any app.
Why Samsung Created *#0*#: The Real Purpose
The *#0*# diagnostic tool wasn’t made for normal users — it was built for:
- Samsung service engineers
- Factory testing before shipment
- Technicians performing repair diagnostic tool
- Advanced users troubleshooting hardware issues
Today, many users have discovered this code and use it to test their devices after drops, repairs, or battery issues.
How to Use *#0*# on Your Samsung Device
Here’s a simple step-by-step guide:
- Open your Phone app.
- Go to the dialer (keypad).
- Type this code:
*#0*# - As soon as you type the last “#”, a hardware diagnostic menu will appear — no need to press “Call”.
If nothing happens:
- Your phone may not support it (we’ll cover that below)
- Your carrier or region might have blocked it
- Your Android version might have disabled it
Samsung Devices That Support *#0*# in 2025
This code is confirmed working on many Samsung models, including:
🔹 Samsung Galaxy S Series:
- Galaxy S21 / S21+ / S21 Ultra
- Galaxy S22 / S22+ / S22 Ultra
- Galaxy S23 / S23+ / S23 Ultra
- Galaxy S24 / S24 Ultra (some variants)
🔹 Samsung Galaxy Note Series:
- Galaxy Note 10 / 10+
- Galaxy Note 20 / 20 Ultra
🔹 Samsung Galaxy A and M Series:
- Galaxy A52, A72, A73
- Galaxy M31, M33, M53, etc. (varies by region)
🔹 Galaxy Fold & Flip:
- Some features may work partially on Fold 4, Fold 5, Flip 5
💡 Note: Carrier-locked phones (e.g., Verizon, AT&T) might block this feature.
What You Can Test Inside *#0*#: Full Menu Breakdown
Once inside the #0# menu, you’ll see a grid of options. Here’s what each one does:
1. 🔴 Red / 🟢 Green / 🔵 Blue:
- Test for dead pixels or screen issues
- Tap each to see solid colors — ideal for display quality checking.
2. ⚪ Dimming:
- Test screen brightness levels and auto-dimming functionality
3. 📱 Touch:
- Test if all parts of the screen respond to touch
- You’ll be asked to draw lines over a grid — useful after a drop.
4. 🔈 Speaker:
- Tests your phone’s main speaker using a tone
5. 🔇 Vibration:
- Activates vibration motor instantly
6. 🎙️ MIC:
- Tests the microphone — will record and playback your voice
7. 📷 Camera:
- Opens camera module test (front & rear)
8. 🔄 Sensor:
- Test gyroscope, accelerometer, proximity sensor, light sensor
9. 🔆 LED:
- Activates LED flash to verify its functionality
10. 🛑 Others:
- Sub-tests like barometer, magnetic sensor, fingerprint sensor, etc. (depending on your device)
If you’re interested in exploring even more powerful and hidden smartphone codes beyond just *#0*#, check out our full guide covering all major brands.
👉 Smartphone Secret Codes 2025 – The Ultimate List for All Major Brands includes working USSD codes, hardware test codes, and advanced settings for Samsung, Xiaomi, Vivo, Realme, OnePlus, iPhone, and more.
Is *#0*# Safe to Use?
Yes, *#0*# is safe to use if you don’t modify or reset anything.
Safe Things to Do:
- Touch and test display, camera, mic, sensor
- Exit the menu safely
Unsafe if You:
- Access other engineering menus you don’t understand
- Try random secret codes like factory resets (
*2767*3855#) - Use it while phone is on low battery
🔁 To exit the menu, press the back or home button.
Devices Where *#0*# Might Not Work
Some users report *#0*# doesn’t open the diagnostic tool. This may happen due to:
- Carrier-locked phones (Verizon, AT&T, T-Mobile USA)
- Region-based software differences
- Android 14 or newer with restricted access
- Samsung Knox-enabled devices with restrictions
- Custom ROMs
Alternative Samsung Codes That Still Work (2025)
Here are other working secret codes in Samsung phones:
| Code | Function |
|---|---|
*#06# | Show IMEI number |
*#1234# | Check firmware version |
*#0228# | Battery status |
*#2663# | Touch firmware |
*#12580*369# | Hardware/software info |
*#0808# | USB settings |
*#7353# | Alternate quick test menu |
These codes also help with diagnostic tool and configuration.
FAQ – Samsung *#0*# Diagnostic Tool
Q1: Why is *#0*# not working on my Samsung?
It may be due to carrier lock, Knox restrictions, or Android 14+.
Q2: Is *#0*# safe to use?
Yes, it’s safe as long as you only test and don’t change settings.
Q3: Can *#0*# factory reset my phone?
No. It’s only a diagnostic tool. Reset codes are different and dangerous.
Q4: How to exit the *#0*# menu?
Simply press the back or home button.
Q5: Does *#0*# work on Galaxy Z Fold or Flip?
Partially — some diagnostic tool may not show properly due to display differences.
Final Thoughts: Should You Use *#0*#?
The code *#0*# is a hidden gem in Samsung phones. Whether you’re testing a used phone, verifying repairs, or checking your hardware — this tool gives you access to tests without needing apps or tools.
But always remember:
- Don’t press anything you don’t understand
- It’s a read-only mode for tests — not for settings or modifications
- Ideal for anyone buying/selling phones
Overall, *#0*# is one of the most useful tools Samsung users can access without any apps.
Bonus Tip:
Learn more about working mobile codes like *#0*# in our full guide.
If you’re interested in more hidden Samsung features like *#0*# or other smartphone secret codes, check out our full list of working codes here:
👉 Smartphone Secret Codes 2025 – The Ultimate List