1. Design

The differences between the series 4 and 3 comes majorly in the design plus additional and improved sensors. No doubt the series 4 has a more appealing , elegant and beast-like design which commands respect and class. The case material are almost the same except that the series 4 has a more durable all ceramics and sapphire crystal back while the series 3 has a composite back(center).

The series 4 has fine finishes and extended curved areas which makes the screen size bigger with 1.78 inches while the series 3 is 1.68 inches. So obviously you see more at a glance with the series 4.

The series 4 and 3 both come with an OLED Retina display that features a bright and high-quality display, but the series 4 comes with additional LTPO technology which the company says will improve battery efficiency which will let you go longer on a single charge.

It’s worthy to note that the series 4 weighs far less than the series 3, despite the fact that the later is bigger, has more features. The series 4 is surprisingly thinner with 10.7mm thickness size while the series 3 is 11.4mm thick.

In previous versions of the Apple watch series, they always come in 42mm and 38mm case sizes respectively, but that has been abandoned as the new series 4 comes in a bigger 44mm and 40mm case sizes respectively due to the increased size.

The digital crown found in series 3 is also here in the series 4, but this time with haptic feedback which delivers a precise click-like feel as you scroll.

2. Platform and Connectivity

The new Apple watch series 4 runs on Apple watch OS version 5.0 while the series 3 runs on version 4.0 but its upgradable to version 5.0. Secondly the series 4 is powered by a stronger S4 dual-core processor with W3 Apple wireless chip which the company says is 2x faster than the S3 dual-core processor and W2 in the series 3.

Beside this ,the series 4 comes with a newer version of Bluetooth v5.0 compared to the v4.2 both LE found in the series 3 which means a more faster connectivity on the series 4.

3. Media

With the series 3, we had 8GB storage space while in the series 4 it is 2x, 16GB storage space, quite massive. With this, you can store all your favorite tracks, videos, and other files. The RAM size of the series 4 is not yet confirmed, but we stipulate that it won’t be lower than the 768MB RAM size that obviously powers the series 3.

4. Sensors

The Apple watch series 4 has a new ECG sensor that lets you take ECG reading simply by pressing the digital crown for about 30 seconds, it then stores the recorded ECG report in the Health app which you can download as PDF and share with your doctor

Beside this , you will find every other sensor on the series 3 on the series 4, but with the series 4 there is an improved accelerometer, gyroscope, second-generation heart rate sensor all upgraded and obviously more smarter and accurate stats from your fitness activities.

The accelerometer is capable of detecting accidental falls the watch will display a message that makes it easy to call emergency services, however, if you are unresponsive for about 60 seconds the device will make a call and also sends a message to your designated emergency contact. This feature is set by default for older people 65 years and above while it can be enabled manually for ages lower than 65.

The new second-generation optical heart rate sensor is also capable of detecting irregular heart rhythms such as unusual low heart rate and warn you about it. This feature and like that of the ECG will come in a later software update on the series 4.

5. Battery

There is no much difference on the battery life, its still same li-ion battery type, couldn’t find the capacity, but Apple says that on average you should expect about 18 hours battery life on the series 4 just same as series 3, but with the minute detailed advancement in technology that comes with the series 4 perhaps you should expect additional 1-4 hours extended battery life.

6. Price

Obviously the price of the Apple watch series 4 will be more than the series 3. Though the discrepancy won’t be much. The aluminum casing are cheaper than the stainless steel casing ranging from $300 to $400, while the aluminum or stainless steel versions with cellular functionality are more costlier and the price ranges from about $500 to $700 respectively.