Wearables and its penetration in our market have been extraordinary. With the likes of MI & Honor offering tons of features at rock bottom prices, it's highly lucrative.And here is MI with a new band in its series, MI Band 4, as a successor of the highly acclaimed previous model, MI Band 3. I got it as an upgrade to both MI Band 3 & Honor Band 4. Find comparisons at the end.As usual, the review is also going to be a detailed one. So grab some popcorn & enjoy it. Get all your queries answered here and if anythings left, feel free to comment here or on my Abstractotech channel or you can contact me directly via Amazon Profile Page.UPDATE 12/10/19: Detailed battery backup analysis with 4 scenarios below. Upto 44 days battery backup! ⚡ ⚡••••••••••••••📜 INDEX••••••••••••••A) Initial views, Inbox, About device, Pros, ConsB) Features as an activity tracker, Other featuresC) Initial Setup, General gesturesD) Step counting (pedometer), Heart rate sensing, Sleep trackingE) Notifications & message threads, MI Fit & Google Fit app, Music control, Weather, BluetoothF) Watch faces & How to set custom watch face, Battery life, Screen Guard, Firmware updateG) MIB4 vs MIB3, MIB4 vs HB4, MIB4 vs HB5, Verdict•••••••••••••••••••••••💭 INITIAL VIEWS•••••••••••••••••••••••Having this device in hand feels good. Nice finish, color display (a first for MI Band series), premium looks (i prefer strap of MI band over Honor), comfortable strap, etc. There is a lot inside. There are a few hiccups too, but they can easily be ignored at this price point. So let's dive into the details.••••••••••••••🎁 INBOX••••••••••••••→ MI Band 4 capsule→ Black wrist strap→ Charging cradle with pogo pins & fixed USB cable (6 inches long)→ Mini user guide••••••••••••••••••••••••🅰 ABOUT DEVICE••••••••••••••••••••••••→ Weight: 22g, Capsule: 12g→ Screen: 0.95" Color AMOLED touch screen with 120 x 240 pixels, 400 nits→ RAM/ROM: 512 KB/ 16MB→ Touch button: wake up or go back→ Sensors: 3 axis accelerometer, 3 axis gyroscope, PPG heart rate sensor, capacitive proximity sensor→ Bluetooth: v5.0 (BLE)→ Battery: 135 mAh LiPo1. Screen 10/10 (+1 for sunlight legibility)2. Battery 9/10 (backup details below)3. Performance 9/104. Build 10/105. Sensors 9/106. BT Range 10/10 (approx 40-50 ft, with no walls in b/w)7. Charging System 7/10 (inconvenient to remove capsule every time to charge it)▶ Overall: 9.1 which translates to 4.55 star, so a 5-star device•••••••••••••➕ PROS•••••••••••••1. A budget device with a very good feature set.2. High-resolution color AMOLED touch display with 2.5D curved tempered glass.3. Extra touch button below the screen to act as back or screen on the button.4. Device is responsive with fast and accurate touch.5. Lightweight (22g only), compact and comfortable. You won't even feel it on hand.6. Very good sunlight visibility as opposed to pathetic one in MI Band 3.7. Impressive battery life. (detailed analysis below)8. Water-resistant up to 50 meters. So rain, underwater, pool, shower, etc won't stop you. Tested it underwater and had no issues.10. Decent list of activities it can track, with swim mode auto recognition & GPS support via MI Fit app.11. Fast & fairly accurate heart rate sensor with 24x7 tracking with user-set interval.12. Sleep tracking with light, deep & sleep quality index.13. Virtually unlimited watch faces including custom photos for watch faces.14. 5-day weather forecast in band.15. Music control possible, play, pause, next, previous, volume +/-.16. Music controls work for YouTube videos also.17. Easy initial setup. Step by step instruction is below.18. Easy to use & well-organized interface.19. Autosync of data to MI fit app.20. Compatible with both Android & iOS devices.21. Replaceable strap to swap colors.22. Compatible with MI Band 3 straps.23. 5 Step adjustable screen brightness with night mode.24. Can be synced with google fit app.25. Flat-screen with 2.5D edges is less prone to scratches unlike MI band 3.26. Alarms created in-app are accessible via band. (on/off)•••••••••••••➖ CONS•••••••••••••1. Every time for charging we need to remove the capsule from strap which is highly inconvenient. Any solution like the one in Honor Band will be highly appreciated.2. Frequent removal of the capsule will eventually loosen it in the strap (this may take months or maybe years), and someday you may find it accidentally missing from the strap.3. Snap-fit type strap looks cool but by design is less secure as compared to normal watch like strap where the strap goes inside buckle and is securely held there by a pin.4. As opposed to the Chinese version, there's no mic or NFC here.5. Incompatible with MI Band 3 charging dock.6. Small charging cable.7. Proprietary charging dock with pogo pins. Micro USB would have been better as its handy. But maybe water resistance ate it up.8. No built in GPS but i think enough is already there.9. No built in camera control but geeks will be able to enable it.10. Sleep monitoring can't be switched off to save battery.•••••••••••••••••••••••••••••••••••••••••••••••🧰 FEATURES AS ACTIVITY TRACKER•••••••••••••••••••••••••••••••••••••••••••••••1. 6 workout modes: Treadmill, Exercise 🏋, Outdoor Running 🏃‍♀️, Cycling 🚴, Walking 🚶, Pool Swimming 🏊 (with laps, strokes & distance tracking)2. Regular Step counting, distance covered, calories burned, duration, etc3. Health monitoring4. Workout completion notifications, goal setting, targets, etc5. Automatic sleep monitoring6. Heart rate monitoring: all-day heart rate checking, resting heart rate, etc7. Water-resistant up to 50mtr so can easily be worn while swimming 💦8. Idle alert or sedentary reminder (with start & end time)••••••••••••••••••••••••••••🧰 OTHER FEATURES••••••••••••••••••••••••••••1. Vibration alarm (You can set any no of alarms, i tried to set 10 alarms & it worked. Just that band's alarm interface becomes slow with many alarms)2. Call silent or reject3. Proximity sensor to switch off the display when you cover the full screen with palm or any object4. Pre-set & customizable watch faces5. Band lock screen6. Timer, stopwatch7. Notifications, incoming calls, message, calendar, apps, events, etc8. Weather forecast of up to 5 days9. Find phone10. Phone unlock11. Phone silent or normal mode from the band.12. Night mode, Do not disturb mode (works even without phone)13. Music controls to play, pause, next, previous, volume +/- for music on the phone14. Music controls also work for YouTube videos15. Bluetooth broadcasting16. Band lock screen can be set to unlock band on swipe only.17. OTA updates18. Lift wrist to view info19. 5 steps adjustable brightness20. All notifications are displayed in the form of screen animation & vibration21. Custom vibration pattern can be defined via app in many places••••••••••••••••••••••🛠 INITIAL SETUP••••••••••••••••••••••Pairing & initial setup of the band is as easy as 1,2,3. The band comes already charged & if you touch the button below the screen, it lights up & says "Pair First". You just need to download the app (Android or iOS) & follow the instructions below:1. Turn on phones Bluetooth2. Open the app & click on + on top right or go to Profile → Add Device3. Select Band & allow the required permissions4. Bring the band closer to the phone5. When band vibrates, tap on tick mark to pair6. Paired message is displayed on the app. If available, band firmware will update automatically7. Continue & configure notifications, band preferences, etc8. Enjoy your device. It's ready to use•••••••••••••••••••••••••••••••✌ GENERAL GESTURES•••••••••••••••••••••••••••••••▶ COVER FULL SCREEN- Screen off▶ TOUCH BUTTON- Go back- Wake band▶ SCREEN SWIPE- Top to bottom to scroll downwards- Bottom to top to scroll upwards- Right to left to return to the previous page▶ BAND- Lift wrist to view info••••••••••••••••••••••••••••••••🏋 WORKOUT SESSIONS••••••••••••••••••••••••••••••••- No built in GPS but phone GPS can be used via the MI Fit app.- Max workout modes work without app connectivity, just that band won't record route via GPS.- Cycling does not work without mobile connected. Like other modes, it informs that the route won't be recorded but goes back to the main screen (maybe a glitch).- Every data is recorded in band & synced upon app connectivity.- Heart rate also recorded. Make sure to switch on "activity detection" for better accuracy if the frequency is set to higher values.- Music can't be controlled while in workout mode. You need to stop it to be able to control music.••••••••••••••••••••••••••••••••••••••••••••••••🔢 PEDOMETER OR STEP COUNTING••••••••••••••••••••••••••••••••••••••••••••••••- Band automatically counts the steps & displays data in "status" entry- Steps, distance, calories, & idle alerts are shown- Step counting is fairly accurate. My 100 steps were counted as 109 by MI Band 4 & 107 by Honor Band 4- During night no steps count was there. Some band erroneously count steps during sleep alsoTEST- Manual count of 660 steps- MI Band 4: 695- Honor Band 4: 684•••••••••••••••••••••••••••••••••💗 HEART RATE SENSING•••••••••••••••••••••••••••••••••- Fairly accurate sensor.- Takes approx 20 s before showing current rate & then final avg at the end of the 60s- Heart rate detection modes: Automatic, Sleep assistant, Continuous (automatic + sleep assistant)- Detection frequency can be set, 1 or 5 or 10 or 30 mins- Activity detection can be set to auto increase frequency during workouts- Heart rate alert after 10 mins of set BPM. It won't work if the frequency is set to 30 mins- Detailed data available in Fit appTEST- Manual check: 87- Omron BP monitor: 86- MI Band 4: 91- Honor Band 4: 88•••••••••••••••••••••••••••💤 SLEEP TRACKING•••••••••••••••••••••••••••- Sleep tracking is automatic.- It records: bedtime, wake up time; deep sleep, light sleep, time awake, full sleep duration- Heart rate monitor can be set to sleep tracking mode or continuous mode for further accurate sleep data- Activating the above setting has a severe effect on the battery- No sleep data available in-band interface- No REM sleep data- No day time sleep trackingTEST Night 1:- Actual sleep 6 hrs 35 mins- MI Band 4: 7 hrs 30 mins- Honor Band 4: 6 hrs 42 mins Night 2:- Actual sleep 6 hrs 30 mins- MI Band 4: 6 hrs 49 mins- Honor Band 4: 6 hrs 42 mins•••••••••••••••••••••••••••••••••••••••••••••••••••••✉ NOTIFICATIONS & MESSAGE THREADS•••••••••••••••••••••••••••••••••••••••••••••••••••••- Open notifications to view app notifications & messages- Notifications/msgs are displayed in reverse order as per the time of push- Swipe up to read them one by one- Once you reach the end of it, keep swiping to read the next notification/msg- Swipe down to delete all from the band- Multiple WhatsApp messages can also be read, one by one- It even displays 300-400 words WhatsApp message without any issue or lag•••••••••••••••••••••••••••🎵 MUSIC CONTROL•••••••••••••••••••••••••••- ⏯⏮⏯ 🔉🔊 Pause, play, next, previous, vol +, & vol - works well. You can't fast forward songs- Make sure the MI Fit app has notification access. Without it, music controls won't work- You can only control the music using the band, but not start it initially- If you just open the music app, & don't play any song, it won't work. "No music is playing"- Once you start the music, then you can fully control it- Works flawlessly with all music apps like Prime, Spotify, Wynk, etc- Bonus is it works with Youtube videos also, with all controls- Doesn't work with other video streaming apps••••••••••••••••••⛅ WEATHER••••••••••••••••••- Displays 5 days weather forecast as per city set in Fit app- The first screen shows current day weather- Scroll screen to display the next 4 days forecast, 2 days at a time- Scrolling here was a bit laggy••••••••••••••••••••••📶 BLUETOOTH••••••••••••••••••••••- Comes with BT 5.0 (low energy)- No frequent disconnections witnessed- The range is quite good at approx 40-50 ft without walls- Unlock mobile using the band via BT- Once out of range app & band displays disconnection- Once the band comes in range, app auto connects to it•••••••••••••••••••••••⌚ WATCH FACES•••••••••••••••••••••••- 3 Builtin watch faces- A good collection is available via the Fit app- Custom watch face also supported with any photo from the gallery- Takes approx 15-20s to sync watch face to the band▶ SET CUSTOM PHOTO WATCH FACE- Open MI Fit app- Go to band display settings -> Custom, and select layout- In next screen, click on change background & select gallery- Crop photo using any of available app- Sync face to the band••••••••••••••••••••••🔋 BATTERY LIFE••••••••••••••••••••••There are various parameters affecting battery viz BT, Heart rate monitor, Screen on time, etc. Each having its own impact wrt on/off. So backup can vary by large means depending on usage pattern.▶CHARGING TIME (0 to 100%) : ~1.5 hours via USB 2.0 Port(Battery Capacity: 135 mAh, After 0%, the battery drained till auto-off, before charging)▶COMPANY CLAIMS (Backup): 20 days▶REAL-WORLD USAGE (Backup) (Brightness full level 5 in all cases)i) Full load, Everything "on": 14 Days 6 Hours ✔- As per scaled data (26% drop in 96 hours)- Heart rate, automatic + sleep assistant is "on", 1 min frequency, activity detection "on"- 20 min daily cycling- Alarms (2), idle alerts, call & SMS alerts, Lift wrist to view info are on- Night mode is off- 24x7 connected to mobileii) Medium Load: 22 Days 5 Hours ✔- As per scaled data (18% drop in 96 hours)- Heart rate in sleep assistant mode- 20 min daily cycling- Alarms (2), idle alerts, call & SMS alerts, Lift wrist to view info are on- Night mode is off- 24x7 connected to mobileiii) Light Load: 26 Days 14 Hours ✔- As per scaled data (15% drop in 96 hours)- Heart rate, automatic mode is "on", 30 min frequency, activity detection "on"- 20 min daily cycling- Alarms (2), idle alerts, call & SMS alerts, Lift wrist to view info are on- Night mode is off- 24x7 connected to mobileiv) Very Light Load, Everything "off": 44 Days 10 Hours ✔- As per scaled data (9% drop in 96 hours)- Heart rate monitor off- No workout- Idle alerts, SMS alerts, Lift wrist to view info is off- Night mode (10 pm to 7 am), Alarms (2) are on- Connect to mobile & sync to the app, once in a day▶ GENERAL INSIGHTS & TIPSa) With everything off, as in you are using it as a watch & step counter. Though this defies its sole purpose, you get super max battery lifeb) Switch off "Lift wrist to view info" to save battery. As it will light up screen unnecessarily every time, even when you don't desire to look atc) Switch of band discovery in settingsd) Keep night mode on to save battery•••••••••••••••••••••••••••••••••••••••📱 SCREEN GUARD YES OR NO•••••••••••••••••••••••••••••••••••••••Having a screen guard looks tempting & is sometimes handy, but if you are careful enought you won't need it. Even it affects the looks of the band. These devices are not meant to last forever, so enjoy till it lasts.Another issue is due to the 2.5D screen. Already small screen with 2.5D curves, a guard won't be able to cover full area and there will be gaps on the edge, which will look ugly. A similar issue is faced with 2.5D edges in mobiles.Also, 2.5D is responsible for accidental peel off of the protector as bands swipe across a lot of things (esp non-scratching ones like clothing, persons, pillow during sleep, etc). I lost two screen protectors from Honor band 5 in a similar way, after which i stopped using these on bands.••••••••••••••••••••••••••••••📲 FIRMWARE UPDATE••••••••••••••••••••••••••••••Latest: v 1.0.6.16 as on 21.09.2019- OTA updates are provided from time to time. First, it's downloaded in the phone & then transferred to the band via BT- Received firmware update as soon as the device was connected- It takes 3-4 minutes for the process to complete- IT first updates resources & then the firmware- During the process, the band will display "updating" & nothing will work••••••••••••••••••••••••••••••••MI BAND 4 vs MI BAND 3••••••••••••••••••••••••••••••••Its a definitive upgrade for those with MI Band 3.- 0.95in 120x240px colour AMOLED screen in MB4 vs 0.78in 128x80px monochrome OLED in MB3- Awesome sunlight legibility in MB4 vs pathetic in MB3- Built in music controls in MB4 vs none in MB3- Battery 135 mAh vs 110 mAh in MB3- BT 5.0 in MB4 vs 4.2 in MB3- Unlimited & custom watch faces in MB4 vs few in MB3- Flat tempered glass above screen in MIB4 vs more scratch-prone oddly curved plastic one in MIB3•••••••••••••••••••••••••••••••••••••••MI BAND 4 vs HONOR BAND 4••••••••••••••••••••••••••••••••••••••It's a so so upgrade if you already have previous Honor Band 4 as Honor Band 4 already has many of the features. Some extras in MI Band 4 are:- Music Control via Band in MB4- BT 5.0 in MB4 vs 4.2 in HB4- Unlimited watch faces in MB4 vs few in HB4- Flat-screen with 2.5D edges vs curved screen with 2.5D edges in HB4- Alarms created in-app are accessible via the band•••••••••••••••••••••••••••••••••••••••MI BAND 4 vs HONOR BAND 5•••••••••••••••••••••••••••••••••••••••This is the current trend and if you don't have any band & are looking for one, then it's important to check on both.▶ Departments where MI Band 4 is better:- Premium looking band- Comfortable watch strap- Nothing specific to MI Phones- Slightly better battery life- Better spare strap availability due to MI's own store- Custom watch faces (use your gallery photos in watch face)- "Always on" band, unlike Honor band where you have the option to power off the band & then if you're without charging cradle, you cant switch it back on- Flat tempered glass screen with 2.5D edges, which is less prone to scratches- Alarms created in-app are accessible via the band- Cheaper▶ Departments where Honor Band 5 is better:- True sleep mode with REM sleep tracking- SPo2 sensor to check oxygen levels in the blood- Sleep time breathing data- No need to remove the strap for charging- Normal watch like strap where the strap goes inside buckle and is securely held there by a pin- More workout modes (10, vs 6 in MB4 )- Accuracy here is slightly better in all domains••••••••••••••••🏆 VERDICT••••••••••••••••Fitness tracking is getting crazy these days with every other person looking for a band. With the likes of MI, fitness tracking has gone to another level. Too much for too little. MI made it reach the hands of almost everyone looking for fitness tracking.There are a few minor issues here & there, wrt accuracy & software glitches which can be fixed in fw updates.▶ 🆙 UPGRADING?→ I already own MI band 3 & Honor Band 4. Comparing MB3 & MB4, MI band 4 is a definitive upgrade with a good set of new features. (comparison above)→ If having Honor Band 4, the upgrade won't matter much. Only upgrade if you want to have some extras, change of experience & different ecosystem. (comparison above)▶ 🆕 NEW TO WEARABLES?→ If your budget is low & can ignore things quality & features discussed above, go for any cheap quality band.→ If you can extend your budget, then definitely go for MI Band 4 without any second thought. It's right now the best wearable available for the price.→ If you can extend the budget further by a few hundred, then go for Honor Band 5, as its accuracy is slightly better & has more features.→ If you are looking for serious activity tracking, then extend your budget further by 1000's and get some serious fitness tracker. Remember these are budget devices & expect similar features & performance. Don't expect wonders & get disappointed to rate them low.