Smartphones aren’t just about flashy apps and sleek interfaces — they also come with hidden menus, diagnostics tools, and secret testing modes that you can unlock with special dialer codes.
Whether you’re using a Samsung Galaxy, an iPhone, a Xiaomi phone, or a Realme device, there are USSD and MMI codes that give you access to deep system information, hardware testing features, and carrier-specific settings.
In this guide, we’ve compiled the largest, most up-to-date collection of smartphone secret codes in 2025, categorized by brand and use case.
Table of Contents
What Are Secret Smartphone Codes?
Secret smartphone codes, also known as USSD (Unstructured Supplementary Service Data) or MMI (Man-Machine Interface) codes, are special combinations of symbols and numbers entered into your phone dialer. They are not visible in the standard menu and are often used by:
- Developers
- Repair technicians
- Mobile network engineers
- Advanced users
These codes can help:
- Access hidden menus
- Test hardware (speaker, display, sensor)
- View detailed phone/battery/network info
- Enable/disable advanced features
⚠️ Warning: Some codes can perform factory resets or change important settings. Use them with caution.
Universal Smartphone Codes (Work on Most Android & iPhones)
Master Diagnostic Codes 2026
*#06# |
Display IMEI & Serial Number |
*#*#4636#*#* |
Network, Usage & Battery Stats |
*#*#1472365#*#* |
GPS Precision Test |
*#*#232339#*#* |
Wireless LAN (Wi-Fi) Test |
*#0*# |
Universal Hardware Test (Samsung) |
*#*#8351#*#* |
Enable Voice Call Logging |
*#*#8350#*#* |
Disable Voice Call Logging |
These codes may not work on all phones due to software restrictions or regional lockouts.
Best Smartphones Under $300 in 2025
Apple iPhone Secret Codes
Unlike Android, Apple doesn’t support USSD for diagnostics, but you can access some hidden functions via these codes:
iPhone & GSM Secret Codes
📌 Note: These codes open system-level call/network settings and do not offer hardware diagnostics like Android.
Samsung Secret Codes (One UI 6 / Android 14)
Samsung phones offer one of the most powerful hidden menus for diagnostics:
Samsung Deep Diagnostics
Samsung – More Hidden Diagnostic Codes
*#*#34971539#*#*– Camera firmware & hardware info*#*#197328640#*#*– Samsung service mode (advanced testing)*#*#232338#*#*– View Wi-Fi MAC address*#*#232331#*#*– Bluetooth test mode
These Samsung secret codes are mostly read-only and are useful for checking hardware details before buying a used phone.
Xiaomi / Redmi / POCO (MIUI 14/15)
Xiaomi/POCO Engineering Mode
Xiaomi / Redmi / POCO – Extra Testing Codes
*#*#64663#*#*– Full hardware diagnostic test*#*#6484#*#*– CIT engineering test menu*#*#4636#*#*– Phone, battery & network information
These codes are especially helpful on MIUI and HyperOS devices for sensor and hardware verification.
Realme / Oppo (ColorOS)
MTK & BBK Engineering Hub
📌 Note: Many codes may not work in newer ColorOS 14+ due to UI restrictions.
Vivo Secret Codes
Vivo Diagnostic Toolkit
OnePlus (OxygenOS 14+)
Realme & OPPO Tech Toolkit
Advanced Engineering Switch
OnePlus – Advanced Diagnostic Codes
*#808#– EngineerMode (manual hardware testing)*#*#4636#*#*– Network, battery & usage statistics*#*#759#*#*– Factory testing menu (older OxygenOS models)
Some OnePlus codes may vary depending on OxygenOS version and region.
Huawei / Honor
Huawei/Honor Engineering Hub
Network Info, Software Updates & Battery
Motorola (Android One)
Motorola Engineering Hub
Hidden Carrier Control Menu
Nokia (Android One Series)
Universal Android Toolkit
*#*#7780#*#* le phone ko Google account settings ra downloaded apps haru delete garchha. SD Card ko data chai erase hudaina, tara settings sabai reset hunchhan.
Motorola / Nokia (Android One Devices)
*#*#4636#*#*– Network and battery information*#*#2486#*#*– Hardware diagnostic menu (supported models)
Android One devices usually support fewer brand-specific codes but still allow basic diagnostics.
How to Use Secret Codes Safely
Before using any smartphone secret code, keep these points in mind:
- Always enter codes in the Phone dialer, not in settings or browser
- Read-only codes are safe, but reset or factory codes can erase data
- Backup your data before using advanced diagnostic or reset codes
- Some codes may not work on carrier-locked or region-restricted phones
- If a menu opens automatically, do not change settings unless you know what they do
Secret codes are meant for testing and information, not for unlocking or bypassing phone security.
Practical Use Cases
You can use smartphone secret codes to:
- Check hardware condition before buying a used phone
- Diagnose battery, sensor, or network issues
- Verify IMEI and device authenticity
- Test camera, display, speaker, and vibration without apps
These codes are especially useful for technicians, resellers, and advanced users.
Warning: Use With Caution
- ⚠️ Some codes perform irreversible actions like resetting your device.
- 📵 Some codes are disabled by default on carrier-locked or newer phones.
- 🧪 Use only the codes you understand — especially those under “engineer mode” or “reset.”
Frequently Asked Questions (FAQ)
Q1: Why don’t some codes work on my phone?
Some codes are disabled by manufacturers, carriers, or vary based on Android version.
Q2: Can I unlock hidden features using these codes?
Yes, but most features are read-only. Some may unlock test modes or settings.
Q3: Will using secret codes void my warranty?
No, simply entering codes usually doesn’t void warranty — unless you change system settings or root the device.
Q4: Are these codes safe to use?
Most are safe if used to view information. Avoid reset or engineer codes unless you’re sure.