How to properly tie the fitness bracelet Xiaomi Mi Band 4 to another phone: a step-by-step guide with a photo

Switching to a new smartphone is always an exciting process, especially when it comes to synchronizing gadgets like the Xiaomi Mi Band 4. Many users face problems when trying to tie the bracelet to another phone: the application does not see the device, the data is not transferred, then synchronization errors occur. In fact, the procedure is quite simple, if you know all the nuances and follow the proven instructions.

In this article, we'll look at three key scenarios: how to transfer the wristband from one phone to another with data saved, how to tie it to a new device from scratch, and what to do if the Mi Band 4 refuses to connect, and you'll learn about hidden settings that will help avoid typical errors, and you'll get a checklist for quick diagnosis of problems. Whether you're switching from Android to iPhone or just changing your smartphone on the same platform, our recommendations cover all cases.

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

Before you can tie the Mi Band 4 to a new phone, you need to properly end the old device, which will prevent data loss and make it easier to sync further.

📱 Update the Mi Fitness app (formerly Mi Fit) on both phones to the latest version.Outdated versions often don't support correct data portability.
🔄 Sync all data with the Xiaomi cloud manually: open the app, go to the bracelet profile and click "Sync".

Pay special attention to cloud sync. If you are not logged in to Xiaomi or Mi Account, all data (steps, sleep, pulse) will be lost when unbundled. You can check sync status in Profile → Settings → Data Sync.

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If you use an iPhone, turn off Battery Optimization for the Mi Fitness app in your iOS settings before untieing the bracelet.

Also, the Mi Band 4 supports simultaneous tethering to only one phone, and if you try to connect it to a new device without decoupling from the old one, there will be a conflict and the bracelet may stop responding to notifications.

Step 1: Untie the bracelet from the old phone

To tie the Mi Band 4 to a new smartphone, you first need to remove it from your old one correctly, a process that differs depending on whether you plan to save data or not.

Method 1: Data retention decoupling (recommended)

Open the Mi Fitness app on your old phone.
Go to the Profile section → Mi Smart Band 4.
Press three points (⋮) in the upper right corner and select Remove the device.
Confirm the action and wait for the sync with the cloud to be completed.

Method 2: Completely reset the bracelet (if you don't have access to your old phone)

If you can’t use an old device (for example, it broke or lost), perform a hardware reset:

On the bracelet, go to Settings → Additional → Reset (scroll the screen with swipes up and down).
Confirm the reset by clicking the tick (✓). The bracelet vibrates and resets.
After the reboot, it will appear on the screen. QR-rebound.

What happens if you don't untie the bracelet before you tie it to a new phone?

If you ignore the junction, the new phone will not be able to connect to the Mi Band 4, as the bracelet will remain “tied” to the old device in memory. at best you will see the error “Device is already connected”, at worst – the bracelet will not respond to any attempts of synchronization, and you will need a complete reset with the loss of all local data (for example, alarm clocks or screen settings).

Important: After resetting, all local settings (alarm clocks, notifications, screen order) will be deleted, but activity data synchronized with the cloud will remain available after re-entering the account.

Step 2: Install the app on a new phone

Before you plug in the bracelet, make sure the new phone has an official app installed and configured. For the Mi Band 4, only Mi Fitness (formerly Mi Fit) is suitable, as the Zepp Life is designed for newer models (starting with the Mi Band 5).

For Android:

📥 Download Mi Fitness from Google Play.
🔑 Log in to the same Xiaomi account as your old phone (this is critical for data recovery!).
📶 Enable Bluetooth and geodata permissions (required to find devices).

For iPhone (iOS):

📥 Install Mi Fitness from the App Store.
🔑 Use the same Mi Account as before. If you don't have an account, register a new one (but the data from your old phone won't be transferred!).
🔒 In iOS settings, allow the app to access Bluetooth, Notifications and Health (optional).

📊 What phone do you use with Mi Band 4?

Android

iPhone

Both (and Android and iPhone)

Other

If you don’t remember the login details for Xiaomi, restore them through the official website. Without authorization, synchronization between phones will not be possible.

Step 3: Linking the bracelet to a new phone

Now you can start connecting. The process is a little different depending on whether you've reset the bracelet or just untie it through the app.

If the bracelet has been dropped (shows) QR-code):

Open Mi Fitness on your new phone.
Click Add Device (+) → Bracelet → Mi Smart Band 4.
Put the phone camera on QR-If the scan is not working, select Manually Connect.
Follow the instructions on the screen: Confirm the pairing in the phone’s Bluetooth settings.

If the bracelet has not been dropped (untieted via the app):

Turn on Bluetooth on your phone and start Mi Fitness.
Go to Profile. → Add the device.
Select the Mi Smart Band 4 from the list. The bracelet should appear in the "Available Devices" section.
Confirm the connection on both devices (the bracelet will request pairing).

🔹 Bluetooth is on on the phone

🔹 Mi Fitness app updated

🔹 Bracelet loaded (>30%)

🔹 Xiaomi account authorized

🔹 Search mode is enabled on the bracelet (if required)-->

Critical detail: If the bracelet doesn't appear on the list of available devices, reboot Bluetooth on your phone (turn off/on) and restart the app, which solves the problem 80% of the time.

Solving common binding errors

Even if you follow the instructions accurately, you can get into a crash.-5 errors and ways of eliminating them:

Mistake.	Reason.	Decision
"Unable to connect."	Bluetooth conflict or outdated bracelet firmware	Update the firmware through Settings → About the bracelet → Update
"The device is already tethered."	The bracelet was not untied from the old phone.	Reset the bracelet (see Step 1)
The bracelet does not vibrate when notified.	Not given permission to notify on the phone	Check Bluetooth settings and Notifications in Mi Fitness
"No connection to the server"	Problems with the Internet or Xiaomi account	Reconnect to Wi-Fi or mobile network, re-enter your account

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If the bracelet shows the wrong time after the bracelet is tied, synchronize it manually: Bracelet profile → Additional → Synchronize the time.

Pay special attention to application permissions. On Android 10+ and iOS 14+, systems actively block the background of applications, which can interfere with synchronization.

Go to Settings → Applications → Mi Fitness → Permissions.
Enable Geodata, Bluetooth, Notifications.
Disable Battery Optimization for the application.

Transfer data and settings after binding

If you’ve used the same Xiaomi account on both phones, most of the data (steps, sleep, workouts) will automatically sync to the cloud within 5-10 minutes of being connected.

⏰ Alarm clocks: go to Bracelet Profile → Alarm clocks and add them again.
🔔 Notifications: Configure a list of applications, notifications from which will be duplicated on the bracelet.
🎨 Screen order: change the sequence of displayed widgets through the Screen → Screen settings.
🔒 Unlocking the phone: if you used the bracelet to unlock, you will have to re-tether it in the security settings of the phone.

To speed up data synchronization:

Open Mi Fitness and wait for the background synchronization to complete (the indicator at the top of the screen).
Go to Profile → Mi Smart Band 4 → Sync and run the process manually.
Check that the bracelet is synchronized: Settings → Data Synchronization.

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If the data is not transferred, check if the phone is power saving mode, which can block the background synchronization of the application.

On iPhone, syncing can take longer due to iOS restrictions.If data doesn't show up within an hour, try:

Close and reopen the Mi Fitness app.
Reset the bracelet (press the touch button for 10 seconds).
Log out and re-enter your Xiaomi account.

What to do if the bracelet does not connect to the new phone

If the Mi Band 4 stubbornly does not want to mess with the new smartphone, use the diagnostic algorithm:

Check compatibility: Mi Band 4 officially supports Android 5.0+ and iOS 10.0+. On older versions, errors may occur.
Remove junk connections: Go to Settings → Bluetooth on your phone, search the MI Band 4 list (or similar) and delete it. Then try again.
Check the bracelet on another phone: if it doesn’t connect there, the problem is in the bracelet itself (possibly damaged Bluetooth module).
Reset your network settings on your phone: on Android, it’s done through Settings → System → Reset → Reset Wi-Fi, mobile network and Bluetooth.

How to check if Bluetooth is working on a bracelet?

If the bracelet vibrates when you touch it and displays time but doesn't connect to the phone, the problem is more with the phone than the bracelet. Try connecting another Bluetooth device (e.g. headphones) to it. If they don't, too, reset the network settings on the phone.

If nothing helps, try an alternative method of connection:

Install the Notify & Fitness for Mi Band app on your phone (available on Google Play).
Run it and select Connect the device.
Follow the instructions – sometimes it finds the bracelet even when the official app fails.

In extreme cases, contact Xiaomi’s support team by providing:

Phone model and Android/iOS version.
The Mi Fitness version of the app.
Description of the error (screenshot if possible).

FAQ: Frequent questions about the Mi Band tie-up 4

Can I tie the Mi Band 4 to two phones at the same time?

No, the bracelet only supports binding to one device, and if you try to connect it to a second phone, the first connection will be automatically terminated, but the data will sync with the Xiaomi cloud, and you can view it from any device authorized in the same account.

Why did the data from the past days disappear after being linked to a new phone?

This happens if: You used different Xiaomi accounts on the old and new phone, the cloud was not complete until the bracelet was uncoupled, the new phone has the internet shut down during the first sync, try to log out of your Mi Fitness account and log in again, sometimes triggering re-synchronization.

How to transfer alarm and notification settings to a new phone?

Unfortunately, Mi Band 4 doesn't save these settings in the cloud. You have to: Manually restore alarms through the Bracelet Profile → Alarms. Reconfigure notifications in the Bracelet Profile → Notifications. Reconfigure the screen order in the Screen → Set up screens. Take a picture of the settings on the old phone before unsetting - this will simplify the process.

Can I tie Mi Band 4 to a phone without the Mi Fitness app?

Technically, but with serious limitations. You can connect the bracelet through the standard Bluetooth settings of your phone, but: You can't set up notifications, alarms or widgets. There won't be any activity data (steps, pulses) collected. The bracelet will only work like a clock with vibration when you call. For full operation, be sure to install Mi Fitness.

What if the bracelet is permanently turned off when tied to the iPhone?

This is a typical problem because of iOS constraints. Solutions: In your iPhone settings, go to Bluetooth, find MI Band 4 and click "Forget this device." Then re-tether. Turn off Low Power mode in your iPhone settings. In Mi Fitness, turn on the Background Update option. Reboot both the bracelet and the phone. If the problem persists, try tying the bracelet to an Android device, updating the bracelet firmware, and then re-connecting to the iPhone.