Reconnect Xiaomi Mi Band 4 to another phone: full instruction from detachment to synchronization

The Xiaomi Mi Band 4 fitness bracelet remains a popular gadget even years after its release due to its reliability and functionality. However, when changing a smartphone, many users face the problem: how to correctly transfer data and connect the bracelet to a new phone without losing the history of activity? In this article, we will analyze not only the standard reconnection procedure, but also the nuances that the manufacturer does not mention in the official documentation.

The main challenge is that the Mi Band 4 is tied to a Xiaomi account (or Mi Account) rather than the device itself, which means that simply connecting the bracelet to another phone will not work — you first need to break the old binding and correctly synchronize the data, and if you skip this step, you risk losing the sleep, steps and training statistics accumulated over months of use.

Unlike newer models (like the Mi Band 6 or 7), the Mi Band 4 has features in the Bluetooth protocol and pairing algorithm that can cause connection errors. We tested all methods on Android 10–14 and iOS 15–17 devices to provide relevant solutions.

Preparation for reconnection: what to do before the bracelet is unbundled

Before you start resetting your Mi Band 4 settings, make sure that all the preliminary steps are followed, which will help you avoid data loss and synchronization problems.

First, upgrade the Mi Fitness app (formerly Mi Fit) to the latest version.Outdated versions often contain compatibility errors with new smartphones. Check this out on Google Play or the App Store. Second, back up your data via Xiaomi's cloud:

• 📱 Open the Mi Fitness app on your old phone.
• 🔄 Go to Profile. → Settings → Backup of data.
• ☁️ Click on “Sync Now” and wait for the process to be completed.
• 📋 Check that the Devices section displays Mi Band 4 with the current firmware.

If you’re using iOS, check the permissions for the Mi Fitness app in your phone settings: Settings → Privacy → Bluetooth and Health. Without those permissions, sync may be interrupted.

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If you have third-party launchers installed (like Nova Launcher), temporarily return the standard interface. Some shells block background work of Mi Fitness, which interferes with synchronization.

How to untie Mi Band 4 from an old phone

There are three official ways to break the bracelet from an old device, depending on whether you have access to your previous smartphone and whether it runs the Mi Fitness app.

Method 1: Uncoupling through an application (recommended)

This is the safest way to do this, as it stores all data in the Xiaomi cloud:

1. Open Mi Fitness on your old phone.

Method 2: Reset the bracelet to factory settings

If you don’t have access to your old phone, do a hard reset on the bracelet itself:

1. On the Mi Band 4 screen, swipe right to the Settings section (cog icon).
2. Scroll down and select Reset (circle arrow icon).
3. Confirm the reset by ticking the tick. The bracelet will reset.

Method 3: Delete the device via the web version of Mi Account

If the bracelet does not respond to reset, try to remove it through your Xiaomi account:

1. Go to account.xiaomi.com and log in.
2. Select the Device Management section.
3. Find Mi Band 4 in the list and click “Delete”.

Connecting Mi Band 4 to a new phone: step-by-step instructions

Once successfully uncoupled, you can pair the bracelet with a new smartphone, a process that is different for Android and iOS, so we'll look at both.

For Android devices

On Android, the connection algorithm is as follows:

Turn on Bluetooth on your phone |Install the latest version of Mi Fitness | Bracelet Charge > 50% |Authorize in Mi Account (same as on your old phone)

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1. Open Mi Fitness and click Add Device (+ icon).
2. Choose a bracelet. → Mi Smart Band 4.
3. Allow the app to access geodata, notifications and fitness data.
4. Press Connect and confirm the pairing on the bracelet (vibration will appear).
5. Wait for the firmware update (if available).

For iPhone (iOS)

On iOS, there are nuances with notification resolution:

1. In Mi Fitness, select Add the device → Bracelet.
2. When you request to Allow notifications, click Allow (otherwise the bracelet will not vibrate when calling).
3. In the iPhone settings, go to Bluetooth and confirm your connection to MI Band 4.
4. Return to Mi Fitness and wait for the synchronization to complete.

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If the bracelet doesn't connect the first time, reboot the Bluetooth on your phone (turn off/on) and try again. On the iPhone, rebooting the smartphone itself can also help.

Solving common problems when reconnecting

Even with the correct instructions, users often encounter errors, and we've collected the most common problems and ways to fix them.

Critical error: If the bracelet is stuck on the Mi logo after reset and does not respond to pressing, perform a forced reboot. To do this, connect the Mi Band 4 to charging and hold the touch button for 15-20 seconds until the screen goes out.

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If the bracelet is connected but the data is not restored, try manually running synchronization: in Mi Fitness go to Profile → Mi Band 4 → Sync data.

Transferring data from one phone to another

One of the main reasons for data loss when reconnecting is incorrect synchronization with the cloud. To avoid this, follow the algorithm:

1. Check the cloud: on your old phone in Mi Fitness, make sure all data is uploaded to Mi Cloud (Profile → Cloud section).
2. Export history: to Profile → Settings → Export data save backup to Google Drive or to file.
3. Import on a new phone: After connecting the bracelet in the same section, select Data Import.

If your activity history doesn’t automatically recover, try the following trick:

1. Sign in to the same Xiaomi account as the old one.
2. Connect Mi Band 4 and wait for the initial sync.
3. Close the Mi Fitness app (remove completely from the background).
4. Open the app again – sometimes the data is only uploaded after it is re-run.

Set up Mi Band 4 after reconnecting

Once you successfully connect the bracelet to your new phone, you need to personalize it to your needs, and here are the key settings that you should check:

• 🔔 Notifications: In Mi Fitness, go to Mi Band 4 → Notifications and select applications, alerts from which will be duplicated on the bracelet.
• 🌙 Sleep mode: set up automatic sleep tracking in Mi Band 4 → Son → Auto-tracking.
• 🏃 Exercise: Add Frequently Used Activities to Mi Band 4 → Training. → My sports.
• 🔋 Energy saving: If the bracelet discharges too quickly, turn off the constant pulse in the Mi Band 4 → Heart → Measurement frequency.

Pay special attention to the permits for Mi Fitness:

• On Android: Settings → Applications → Mi Fitness → Permissions (enable Phone, Contacts, Calendar).
• On iOS: Settings → Mi Fitness → Notifications (enable Sounds and Badges).

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Once reconnected, the bracelet may require a firmware update. Don't ignore this notification - new firmware versions fix synchronization errors and add support for modern smartphones.

What to do if Mi Band 4 is not connected to a new phone

If the bracelet stubbornly does not want to mate with the new device, try the following diagnostic methods:

⚠️ Note: If you are using Android 12+ or iOS 16+, The problem may be due to new restrictions on the background of applications. In this case, before connecting, add Mi Fitness to the list of exceptions for battery optimization.

Compatibility check

Mi Band 4 officially supports:

• 🤖 Android 5.0+ (but it's recommended 7.0.+ steady-work).
• 🍎 iOS 10.0+ (iOS 17 may have delayed notifications).

If your phone is running an older version of the OS, upgrade it or use a second smartphone to connect.

Alternative methods of connection

If the standard method does not work:

1. Use Developer Mode: Activate Developer Mode on your phone (click 7 times on Build Number in Settings). Enable Bluetooth Debugging in the Developer Settings. Reconnect.
2. Reset network settings: On your phone, go to Settings → System → Reset → Reset your Wi-Fi, mobile network and Bluetooth settings. After rebooting, try connecting again.

⚠️ Note: If the bracelet was previously linked to a Xiaomi account in another region (e.g., the Chinese version of Mi Fit), you may need to change the account region. 1. Sign out of Mi Account in the app. 2. When you re-authorize, select Russia region (or your country). 3. Reconnect the bracelet.

FAQ: Frequent questions about Mi Band 4 reconnection