The Apple Watch 3 and Apple Watch 4 remain popular choices for users who want a capable smartwatch without the latest price tag. Both models build on the same strong foundation but differ in performance, display, and health features.
This comparison focuses on practical differences so you can decide which model aligns best with your daily routine and long term needs.
| Model | Display | Processor | Health Sensors | Battery |
|---|---|---|---|---|
| Apple Watch 3 | 38 mm or 42 mm, 768×384 pixels, OLED, 2.5x brighter than Series 1 | S3 dual-core chip with embedded M9 motion coprocessor | Optical heart sensor, accelerometer, gyroscope, ambient light | Approximately 18 hours |
| Apple Watch 4 | 40 mm or 44 mm, 324×394 pixels, OLED, Always-on readable display | S4 hexa-core chip with embedded W2 and new M12 motion coprocessor | Electrical heart sensor, optical heart sensor, accelerometer, gyroscope, ambient light, onboard ECG app | Approximately 18 hours |
Design and Display Differences
At first glance, the Apple Watch 3 and 4 share a familiar round case shape and digital crown. The Apple Watch 4, however, uses a slightly larger display in each size, thanks to slimmer side buttons and compact internals. The Always-on readable display on the Apple Watch 4 keeps time without raising your wrist, a feature the Apple Watch 3 lacks. Build materials are similar, but the Apple Watch 4 frame feels slightly more rigid, which helps with screen durability.
Performance and Responsiveness
The Apple Watch 4 is notably faster, thanks to the S4 chip and a six-core GPU that improve app launch times and smoother animations. Tasks like scrolling through lists, opening workouts, and responding to notifications feel snappier compared to the Apple Watch 3. The dual-core S3 in the Apple Watch 3 still handles everyday tasks well, but heavier workflows can reveal limitations. If you rely on quick interactions, the performance gap between the two models is meaningful.
Health and Fitness Features
Heart and Electrical Sensors
The Apple Watch 4 introduces an electrical heart sensor that enables an onwird ECG app, providing irregular rhythm notifications that the Apple Watch 3 cannot offer. Both models include an optical heart sensor for elevated heart rate alerts and heart rate during workouts. The Apple Watch 4 also features a high heart rate notification that can trigger earlier warnings during intense activity.
Motion and Fall Detection
Both watches include an accelerometer and gyroscope, but the Apple Watch 4 uses its Motion Coach algorithms more aggressively to adapt workouts and provide smarter feedback. The fall detection feature is present on both, yet the Apple Watch 4 integrates it more deeply with emergency SOS for faster support in critical situations.
Battery Life and Charging
Official Apple estimates place both models at around 18 hours of typical use, but real world endurance can vary based on display brightness, Always-on settings, and app usage. The Apple Watch 4 benefits from a more power efficient S4 chip, which can translate into slightly better battery management over time. Charging mechanisms are the same, so you can reuse existing magnetic cables and docks without extra investment.
Choosing Between Apple Watch 3 and 4
- Prioritize ECG and advanced health alerts, as well as faster performance, choose Apple Watch 4.
- Want a more affordable option with solid core features, the Apple Watch 3 is still a reliable choice.
- Consider future software support, as newer models typically receive updates for a longer period.
- Evaluate your daily use cases, such as workouts, notifications, and health tracking, to match the right model to your routine.
FAQ
Reader questions
Is the ECG feature on Apple Watch 4 available everywhere?
The ECG app is supported in specific countries and regions where regulatory approvals have been granted, so availability may vary depending on your location.
Can I still use fitness apps designed for Apple Watch 3 on Apple Watch 4?
Yes, most third party fitness and utility apps remain compatible, and many developers optimized their apps to take advantage of the faster S4 chip and larger display.
Will my Apple Watch 3 become obsolete after upgrading to Apple Watch 4?
Not immediately, as the Apple Watch 3 remains capable for basic timekeeping, notifications, and fitness tracking if your needs are straightforward.
Does Apple Watch 4 swim proof rating differ from Apple Watch 3?
Both models share the same water resistance rating, making them suitable for swimming and shallow water activities, though manufacturers advise avoiding high velocity water like water sports.