Apple Apple Watch Series 9 (45mm) vs Apple Apple Watch Series 4
Apple Apple Watch Series 9 (45mm) ($124) vs Apple Apple Watch Series 4 ($73) — side-by-side specs, weight, pros and cons to help you pick the right smartwatch.
Spec-by-spec
| Spec | Apple Apple Watch Series 9 (45mm) | Apple Apple Watch Series 4 |
| Price | $124 | $73 |
| Weight | 38.7g | 36.7g |
| Chip | S9 SiP | S4, 64-bit dual-core |
| Case | 45mm aluminium, GPS | — |
| Display | 2000 nit always-on Retina | 30% larger Retina OLED vs Series 3 |
| Water | 50m, WR50 | — |
| Sizes | 41mm and 45mm | — |
| Weight | 38.7g (Apple published) | 36.7g (Apple published, 44mm Aluminum) |
| Sensors | — | Electrical + optical heart sensor, ECG |
| Safety | — | Fall detection |
| WR | — | 50m |
Pros & Cons
Apple Apple Watch Series 9 (45mm)
- Double Tap works one-handed
- 2000 nit display is genuinely bright outdoors
- On-device Siri
- Same case design as the Series 7 and 8
- Battery still about 18 hours
- Blood oxygen disabled on some US units
Apple Apple Watch Series 4
- First Apple Watch with an ECG sensor
- Meaningfully larger display in the same case size class
- Fall detection, a safety feature that debuted here
- Digital Crown haptic feedback, still felt today
- No always-on display
- watchOS support window is closing
- Speaker and mic are a generation behind current models
- Battery health on a used unit is unverifiable before buying
Apple Apple Watch Series 4 is the better value at $73. Both are part of our curated smartwatch index — tap through to check current pricing.