Xiaomi smartphones have become the center of our digital lives, storing sensitive data, banking apps and personal photos. Biometric protection is the first and most important barrier to attackers, so timely updating of scanned data is critical. If you hurt your finger, wear gloves at work or just want to improve the security of the device, the procedure for replacing fingerprints must be done correctly.
The process of changing biometric data in the shells of MIUI and the new HyperOS looks intuitive, but has its own technical nuances. Users often face confusion: can you just add a second finger or necessarily remove the old one? What to do if the scanner stopped responding? In this article, we will discuss in detail the algorithm of actions that ensures the reliable operation of the unlock function.
Note that the quality of the reading depends not only on the software, but also on the surface of the scanner and the finger itself. The fingerprint scanner is a sensor sensitive to contamination and humidity. Before you start setting up, make sure that your hands are clean and dry, and the screen or unlock button is rubbed with a soft cloth without pile.
Device Preparation and Mi Account
Before you make changes to your security settings, make sure your device is biometric ready. First, check if your unlock password is activated (PIN-Android and Xiaomi shells do not allow the use of a fingerprint as the only method of authorization; it always acts as the second factor of confirmation.
It is also crucial to have access to your Mi Account. In some cases, especially after resetting settings or when trying to change critical security settings, the system may request confirmation via your account.
⚠️ Note: If you forget the unlock password, you can’t delete your old fingerprint without losing data, which will require a full Hard Reset, which will delete all files.
Check the battery. Although the setup process takes a little time, suddenly turning off the smartphone while recording biometric data can cause the safety module to fail software, preferably at least 20-30%.
Deletion of old biometric data
The first and mandatory step before adding a new fingerprint is to clear the memory of old, perhaps no longer relevant or poorly readable patterns, and accumulating many “dead” fingerprints can slow down the recognition algorithms as the system has to go through more options.
To do this, go to the settings menu. Find the Passwords and Security section (some firmware versions may simply call it Security). Next, select Unlock by fingerprint. Here you will see a list of all saved fingers numbered 1 to 5 (or more, depending on the model).
Click on the unneeded fingerprint. The system will offer two options: rename or delete. Select the option Remove fingerprint. You will need to confirm the action by entering your master password or PIN-This is a protective measure in case the phone falls into the wrong hands.
- 🗑️ Deleting old data frees up sensor memory and speeds up match-finding.
- 🔒 Password confirmation ensures that only the owner can change the security settings.
- 🔄 It is recommended to remove prints that were recorded long ago and work unstablely.
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Complete removal of old templates before writing new ones is the key to high speed and accuracy of unlocking the device.
Step-by-step: how to add a new print
Once you've cleared the memory, you can start recording a new biometric pattern, and the quality of this procedure has a direct impact on how quickly and how quickly your smartphone will recognize you in the future, so take your time and follow the instructions on the screen.
☑️ Checklist of the perfect print record
In the same fingerprint unlock menu, press the Add fingerprint button. Place your finger on the scanner so that the center of the pad is read. Don't press your finger too hard, but don't touch the surface lightly, you need a confident but gentle press.
The system will start reading, vibrating or sounding every time you successfully capture a piece of land, and your job is to constantly change your finger position, rotate it slightly so that the sensor remembers the edges and the center, and if you use a scanner in the screen, the technology may require you to press different areas of the virtual button.
When the progress bar reaches 100%, the system will prompt you to give a name to the fingerprint (for example, "Right Big"). This is convenient if you plan to store several profiles. After saving, be sure to test the unlock: lock the screen and try to unlock the device with a new profile.
⚠️ Note: When recording a fingerprint, try to keep the phone in the position you normally unlock it (either lying on a desk or in your hand) and this will improve recognition in everyday scenarios.
Advanced settings and acceleration of unlocking
Xiaomi shells offer a number of features that can improve the user experience, one of the most useful is the feature of Accelerated unlock, when activated, the phone unlocks immediately after fingerprint recognition, skipping the swipe step up the lock screen.
But there's a downside to this feature: If you're speeding up, you can accidentally unlock your phone just by picking it up, and in some scenarios, it can interfere with quick access to widgets or notifications on the lock screen without fully unlocking.
How does the algorithm (matching) work?
You can also find the option to unlock when the screen is off in the settings, which allows the sensor to work in sleep mode, consuming minimal energy. If your phone is slow to respond to touch, try turning it off, although on modern Xiaomi models the difference is almost invisible.
- ⚡ Accelerated unlocking saves splits of a second, but requires getting used to.
- 🔋 Background scanning has minimal impact on battery consumption in modern models.
- 📱 On screens. AMOLED The scanner can work a little slower at low brightness.
Table: Comparison of scanner types in Xiaomi
Understanding the type of scanner in your device helps you understand how it works and cares for it. Depending on the model and year of release, Xiaomi uses different biometric technologies.
| Type of scanner | Location. | Principle of work | Features |
|---|---|---|---|
| Capacitive | Back or side | Electric charge reading | High speed, not afraid of bright light, requires physical contact |
| Optical (screen) | On screen. | Light backlight matrix | Works through glass, visible when unlocked, may be slower than capacitive |
| Ultrasonic. | On screen (flagships) | Ultrasonic waves (3D map) | Works with wet fingers, high accuracy, more expensive in production |
Owners of devices with optical scanners in the screen should know that protective glass can affect sensitivity. If you recently changed the glass and noticed a deterioration in the print, perhaps the new glass has too thick adhesive layer or the wrong structure.
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For optical scanners in the screen, use only high-quality protective glass marked "Compatible with fingerprint sensor." Cheap glasses can block the light of the sensor.
Solution: If the print is not working
There are times when, after a fingerprint change or system update, the scanner stops working correctly, the phone can think for a long time, give an error or not respond at all to touch, most often the problem lies in the software failure of the biometric process.
Try rebooting the device. This is a banal but effective tip that helps 80% of the time. If the reboot didn't work, check if the "Gloves" mode or other specific accessibility settings that might conflict with the sensor are on.
In more complex cases, cleaning the system security application data helps. Go to Settings → Applications → All Applications. Go to Security (or Security) and click Clear → Clear all data. Fear not, it won’t delete your files, it will only reset the security application settings.
⚠️ Warning: Clearing the data from the Security app can reset the blacklist settings and some system permissions. Be prepared to reset the prohibitions for unwanted contacts.
If nothing helps and the print doesn't read even after you write it again, it may be a hardware problem, so check if there's any physical damage to the scanner area, cracks on the screen, or traces of moisture.