Apple’s $249 SE 3 Lacks ECG; the $799 Ultra 4 Adds Satellite

Apple sells three Apple Watches: the SE 3 from $249, the Series 12 from $399 and the Ultra 4 at $799. The SE 3 (affiliate link to Amazon, opens in a new tab) drops the ECG and Blood Oxygen apps and the newer S11 chip; the Ultra 4 (affiliate link to Amazon, opens in a new tab) adds satellite messaging, a 100m water rating and the longest battery rating Apple gives. The Series 12 (affiliate link to Amazon, opens in a new tab) is the only one sold in three case materials.

Every price here is from Apple’s US store on 17 October 2026. Apple also sells Hermès editions of the Series 12 and Ultra 4, from $1,399 and $1,499. The Series 11 and Ultra 3 still appear on Apple’s compare page as older models, but not among the watches its store sells.

The three watches

	SE 3	Series 12	Ultra 4
Sizes	40mm, 44mm	42mm, 46mm	49mm
Case	Aluminum	Aluminum, titanium or ceramic	Titanium
Chip	S10	S11	S11
Display brightness, up to	1000 nits	2000 nits	3000 nits
Display glass	Ion-X	Ceramic Shield 2 (aluminum), sapphire (titanium, ceramic)	Sapphire
Battery, Apple’s rating	18 hours	24 hours	50 hours
Low Power Mode	32 hours	38 hours	84 hours
Water resistance	50m	50m, depth gauge to 6m	100m, depth gauge to 40m
GPS	GPS	Precision L1	Dual-frequency L1 + L5
Satellite	None	None	Messages, Find My, Emergency SOS
Dust rating	None listed	IP6X	IP6X

All three have 64GB of storage, the W3 wireless chip, a 4-core Neural Engine, Apple Intelligence and Siri AI on Apple’s compare page, and a 5G-capable cellular version.

Prices on Apple’s US store

Model and case	GPS	GPS + Cellular
SE 3, 40mm	$249	from $299
SE 3, 44mm	$279	Not stated
Series 12 aluminum, 42mm	$399	from $499
Series 12 aluminum, 46mm	$449	Not stated
Series 12 titanium	Not sold	from $699
Series 12 ceramic	Not sold	from $899
Ultra 4 titanium, 49mm	Not sold	$799

Apple’s store pages give a starting price for each option, not every combination, so the cellular price of each larger size is not on the page. On the base aluminum models, the larger size adds $30 on SE 3 and $50 on Series 12, and cellular adds $50 on SE 3 and $100 on Series 12.

A watch for a child who has no iPhone has to be a cellular one: what Apple Watch For Your Kids, formerly Family Setup, needs.

What Series 12 adds over SE 3

On Apple’s compare page the gap is mostly chip, screen and health sensors. Series 12 has the S11 chip against the SE 3’s S10, a wide-angle LTPO3 display at up to 2000 nits against 1000, and Wi-Fi on 5GHz as well as 2.4GHz.

Apple lists the ECG app, the Blood Oxygen app and hypertension notifications on Series 12, and marks all three “Not available” on SE 3. Series 12 also lists the Health Sensing System, a second-generation electrical heart sensor, the Readiness app and Audio Intelligence, none of which the SE 3 column has.

The SE 3 still lists sleep tracking, sleep apnea notifications, wrist temperature sensing, Cycle Tracking, Fall and Crash Detection and the Vitals app, though its Vitals entry omits HRV, which the Series 12 entry includes. Apple names these features; it does not say any of them suits a given person, and neither do we.

Series 12 is also the only model with a choice of materials. Aluminum comes with GPS or GPS + Cellular; titanium and ceramic come only with cellular, and use a sapphire crystal display.

What Ultra 4 adds over Series 12

The two share the S11 chip and the same health feature list on Apple’s compare page. What changes is the outdoors hardware:

• Satellite. Ultra 4 lists Messages, Find My and Emergency SOS via satellite. Apple’s footnote says these are free for two years from activation, and that Find My and Messages via satellite need a carrier plan.
• Water. A 100m rating, a depth gauge to 40m and EN13319 certification; Apple’s activity row reads “Swim, snorkel, scuba, high-speed water sports”. Series 12 is rated 50m, with a depth gauge to 6m, and reads “Swim, snorkel”.
• GPS and sound. Dual-frequency L1 + L5 GPS, dual speakers, a three-microphone array and a siren; Apple’s compare table marks the siren “Not available” on the other two.
• Battery and screen. Up to 50 hours and 3000 nits, against 24 hours and 2000 nits.

It is also the heaviest of the three: Apple lists 63.0 grams for the natural titanium Ultra 4, against 39.5 grams for a 46mm aluminum Series 12 with GPS.

Read the battery figures carefully

Apple’s three battery ratings come from three different tests. Its footnote for the SE 3’s 18 hours lists a workout, notifications and app use over 18 hours, with no sleep tracking. The Series 12’s 24 hours includes six hours of sleep tracking; the Ultra 4’s 50 hours includes twelve. Apple also gives workout tracking separately: 7, 10 and 18 hours.

Charging differs too. Apple says Series 12 reaches 80% in about 30 minutes, and SE 3 and Ultra 4 in about 45.

Before you buy

The newest watches need current iPhone software, which we set out with the full model list in which Apple Watches get watchOS 27. Any Apple Watch pairs only with an iPhone, which is why our smartwatch shortlist is sorted by phone first. If you plan to cover the watch, Apple’s Series 12 store page lists AppleCare+ with Theft and Loss at $4.99 a month; whether AppleCare One costs less across several devices depends on what else you own.

Questions people ask

What is the difference between Apple Watch SE 3 and Series 12?

On Apple’s compare page, Series 12 has the S11 chip, a brighter wide-angle display, up to 24 hours of rated battery, titanium and ceramic options, and the ECG and Blood Oxygen apps. SE 3 has the S10 chip, up to 18 hours, aluminum only, and neither app.

Which Apple Watches does Apple sell right now?

On 17 October 2026 Apple’s US store listed Apple Watch Series 12, Ultra 4 and SE 3, plus Hermès editions of Series 12 and Ultra 4. Series 11 and Ultra 3 were not among its models.

Is the Apple Watch Ultra 4 worth it over Series 12?

That depends on which Ultra-only features you would use. Apple lists satellite messaging and Emergency SOS via satellite, a 100m water rating with depth to 40m, dual-frequency GPS, a siren and up to 50 hours of battery on Ultra 4. Both share the S11 chip and the same health features.

Does the Apple Watch SE 3 have ECG?

No. Apple’s compare table marks the ECG app, the Blood Oxygen app and hypertension notifications as “Not available” on SE 3. It does list sleep apnea notifications, wrist temperature sensing and the Vitals app.

Do I need the cellular Apple Watch?

Apple says a GPS model makes calls and sends messages with your iPhone nearby, and a GPS + Cellular model does it from the watch alone, with a carrier plan. It is also required for Apple Watch For Your Kids. Ultra 4 comes only as GPS + Cellular.

What size Apple Watch should I get?

Each model has its own sizes: SE 3 is 40mm or 44mm, Series 12 is 42mm or 46mm, and Ultra 4 is 49mm only. The larger size costs more: $30 on SE 3 and $50 on Series 12, on Apple’s US store.