Pic Credits Xiaomi
Xiaomi's Mi Band 3 and Mi Band 4 both are the fitness bands also called fitness trackers. The latest version is Mi Band 4 and Mi Band 3 is the older version. Over time such fitness bands are growing in popularity as well as in terms of features. Mi Bands are far cheaper than Apple Watch due to which it's more popular and relatively used by a larger number of people. Let's find the difference between both fitness bands so you can make a better decision:

Xiaomi Mi Band 4 versus Mi Band 3 :

Display:

The biggest upgrade is the change in display. Mi band 3 and the older versions had a Black and White display but now the change has arrived with the Black and White OLED display replaced by Colorful AMOLED display in Mi Band 4.
The size of the Mi 4 band is larger than that of Mi 3, which are 0.95 inches with a resolution of 120×240 whereas Mi 3 has 0.78 inches screen with a resolution of 128×80.
The better screen size and resolution have improved the view quality. Moreover, Xiaomi included 77 different types of the clock face in Mi Band 4 which makes it more customizable.

Design:

Despite the larger screen size of Mi Band 4 is pretty much similar to that of Mi Band 3. Both bands have long and thin bands with the lightweight if 22g for Mi Band 4 and 20g for Mi Band 3. This weight is very small as compared to many other fitness bands.
Both Mi Bands have a silicon band, and there are 5 colors currently available for Mi Band 4 that are black, blue, purple, orange and beige, whereas Mi Band 3 had only 3 colors black, orange and blue. Although all colors may not be launched in all regions as it happened in the case of Mi Band 3.
Both Mi Bands are waterproof up to 50 meters. It means that it is suitable for swimming but not for anything more intensive such as diving.
On both bands at bottom of the display, you get a button to wake the screen and access certain features.

Features:

Both bands have Step tracking, Heart Rate Monitor (HRM), Activity tracking modes such as cycling, running, etc. Although both bands do not have GPS.
Mi Band 4 has a brand new six-axis sensor that allows more accurate and automatic swim tracking. It has a big point that swimmers must notice that is it can identify your swimming style such as Freestyle, Backstroke, etc.
Both trackers can display some notifications such as an incoming call or incoming message but you cannot reply from your fitness band. They both have a battery life of about 20 days. Both bands have weather forecast, alarm and sleep monitor.

Price:

Mi Band 3 is priced at around $30 and Mi Band 4 is priced at around $35 on Amazon.
We can notice there is not much difference in the price. But a point to be kept in mind is that sellers will be providing good discounts on Mi Band 3 as for clearing old stock which will make it worth buying.

The final verdict in my opinion:

Who does not want to have the newest model of technology? So I will be preferring Mi Band 4. Since the price difference is not large enough. So, why not choose Mi Band 4 instead of older version Mi Band 3.

Some good Mi Band 3 and Mi Band 4 alternatives:

·         Honor Band 4 (Price - ~$27)
·         Samsung Galaxy Fit e (Price - ~$33)