Apple Watch Series 11 vs Apple Watch SE 3: ECG Worth $180?

These two watches launched the same day, so this isn’t old-versus-new — it’s flagship versus value. The Series 11 is the default pick if you want a fully loaded watch and don’t care about the price. The real question is whether the SE 3 gives up enough to matter, because at $249 it undercuts the Series 11 by $180 and shares more DNA than Apple would like you to notice.

Key Differences

• Health sensors: The Series 11 has ECG (electrical heart sensor) and blood oxygen; the SE 3 has neither.
• Price: $429 for the Series 11 versus $249 for the SE 3 — a $180 gap.
• Battery: 24 hours on the Series 11 versus 18 hours on the SE 3.
• Screen: Both are always-on OLED, but the Series 11 is larger at 1.96 inches (416 x 496) versus the SE 3’s 1.78 inches (368 x 448).
• Extras: The Series 11 adds a depth gauge, water temperature sensing, and UWB Gen 2; the SE 3 skips all three.

Deep Dive Comparison

Design & Comfort

Both watches use an aluminum case and are rated to 50 meters of water resistance, so both survive swims and showers. The Series 11 is the bigger, heavier watch at 46mm and 37.8g; the SE 3 comes in at 44mm and 32.9g. On a smaller wrist, the lighter SE 3 disappears more easily. Neither feels cheap — the SE 3 doesn’t look like a budget watch, it just is one on the spec sheet.

Battery Life

The Series 11 rates 24 hours of normal smartwatch use; the SE 3 rates 18 hours. Both deliver the same 7 hours with GPS running. In plain terms, the Series 11 comfortably gets you through a full day and overnight sleep tracking, while the SE 3 wants a charge closer to once a day. Neither is a multi-day watch — if that’s your priority, look at Garmin instead.

Health & Fitness Features

This is where the $180 actually goes. The Series 11 carries an electrical heart sensor for ECG readings, a blood oxygen sensor, plus a temperature sensor, depth gauge, and water temperature sensing. The SE 3 has a second-generation optical heart sensor and a temperature sensor, but no ECG and no blood oxygen. Both use single-band GPS and both track workouts, heart rate, and sleep well. If you want on-demand ECG or SpO2 readings, only the Series 11 delivers them.

Smart Features

The smart-watch basics are a wash. Both run the same watchOS, both have a microphone and speaker for calls and Siri, both carry 64GB of storage for music and apps, and both support Apple Pay and cellular LTE (standard on the Series 11, optional on the SE 3). The Series 11 adds UWB Gen 2 for more precise device finding and unlocking, which is nice but not a dealbreaker for most people.

Price & Value

The Series 11 lists at $429; the SE 3 at $249. That $180 buys you ECG, blood oxygen, a depth gauge, a slightly bigger screen, and six more hours of battery. If you’ll use those health features, it’s fair value. If you won’t, the SE 3 gives you roughly 80% of the watch for 58% of the price — and that math is hard to argue with.

Technical Specs

Spec	Apple Watch Series 11	Apple Watch SE 3
Case Size	46mm	44mm
Weight	37.8g	32.9g
Display	1.96-inch LTPO3 OLED, 416 x 496	1.78-inch Always-On LTPO OLED, 368 x 448
Water Rating	50 m	50 m
Battery (Smartwatch)	24 hours	18 hours
Battery (GPS)	7 hours	7 hours
GPS	Single-band	Single-band
Sensors	ECG, optical heart (Gen 3), blood oxygen, temperature, compass, altimeter, depth gauge, water temperature	Optical heart (2nd gen), temperature, compass, altimeter
Storage	64GB	64GB
Payments	Apple Pay (NFC)	Apple Pay (NFC)
Price	$429	$249

The Verdict

For new buyers, the Apple Watch SE 3 is the one I’d hand most people. At $249 it now has the always-on display it was missing, the same 64GB storage, LTE, Apple Pay, and solid workout and sleep tracking — the features you actually use every day. The gaps are ECG and blood oxygen, and plenty of people never touch those.

Buy the Series 11 if you specifically want ECG and SpO2 readings, want the depth gauge for diving or the biggest screen, or want the extra six hours of battery and don’t blink at $429. Buy the SE 3 if you want the best everyday Apple Watch for the money and are fine skipping the clinical-grade sensors. This isn’t close for the average shopper: the SE 3 wins on value, and the Series 11 wins only if you have a real reason to need its extra health hardware.

Frequently Asked Questions

Which Apple Watch should most people buy?

The SE 3 at $249 is the better buy for most shoppers. It covers the everyday essentials — always-on display, LTE, Apple Pay, 64GB storage, and strong workout and sleep tracking — while saving you $180. Only step up to the Series 11 if you want its extra health sensors.

What health features does the SE 3 lack compared to the Series 11?

The SE 3 has no ECG (electrical heart sensor) and no blood oxygen sensor, both of which the Series 11 includes. The Series 11 also adds a depth gauge and water temperature sensing. If on-demand ECG or SpO2 readings matter to you, the Series 11 is the only choice here.

Is the Series 11 worth the extra $180?

Only if you’ll use what it adds: ECG, blood oxygen, a depth gauge, a bigger 1.96-inch screen, and six more hours of battery. For buyers who want those health tools, it’s fair value. For everyone else, that money is better left in your pocket with the SE 3.

Do both watches work the same with an iPhone?

Yes. Both run watchOS and pair with an iPhone identically, with the same notifications, Siri, Apple Pay, and app support. Neither works with Android phones, so both are iPhone-only decisions.

Does the SE 3 finally have an always-on display?

Yes — the SE 3 now uses an always-on LTPO OLED screen, so the time stays visible without raising your wrist. That was a key upgrade over the previous SE, and it closes much of the everyday-feel gap with the Series 11.