Apple Watch SE 3 vs Apple Watch Series 9

Apple Watch SE 3

The big SE 3 story: an always-on display, a first for the SE line. The LTPO OLED panel peaks at 1,000 nits — bright enough for everyday use, but half the Series 11's 2,000 nits and a third of the Ultra 3's 3,000.

• Always-on display arrives on the SE for the first time — Origin Disc: 'that alone is a huge upgrade for the SE line.'
• LTPO OLED panel peaks at 1,000 nits — fine for everyday use but dimmer than rivals.
• 1,000 nits is half the Series 11's 2,000 and a third of the Ultra 3's 3,000 — the SE 3's display is its clearest hardware compromise.
• Always-on is a personal-preference feature — some owners prefer to leave it off for extra battery life.

Apple Watch Series 9

LTPO OLED Always-On Retina display, now 2,000 nits peak brightness — double the Series 8. Can also dim to 1 nit. Bright, sharp, and far more readable in sunlight.

• 2,000 nits peak brightness — double the Series 8's 1,000 nits. Notebookcheck headline: 'Gets brighter, lasts longer.'
• Display can dim to 1 nit — useful in cinemas or at night without disturbing others.
• LTPO OLED Always-On Retina display — sharp, color-accurate, with always-on support.
• Far more readable in direct sunlight than the Series 8 — the brightness jump is the most visible upgrade.
• Same display size + bezels as the Series 8 — the wider display arrived with the Series 10.

Apple Watch SE 3

Heart rate is the SE 3's standout — testers rate it among the best wrist sensors available. Apple adds nightly wrist-temperature tracking and sleep apnea notifications. But ECG, blood oxygen (SpO2), and the Series 11's new hypertension alerts are all absent, and sleep-stage data underreports deep sleep.

• Heart-rate accuracy is excellent — Mike O'Brien tested it against a Polar H10 ECG chest strap and found it had the second-highest correlation of the watches tested, behind only the Pixel Watch 3.
• The Quantified Scientist rates the Apple Watch's optical heart-rate sensor as the best wrist HR monitor he has tested — the SE 3 inherits it.
• No ECG sensor — confirmed missing; if heart-rhythm ECG matters to you, you need the Series 11 or Ultra 3.
• No blood-oxygen (SpO2) sensor and no hypertension notifications — the Series 11's headline health features are absent.
• Apple adds nightly wrist-temperature tracking — the watch samples skin temperature roughly every 5 seconds overnight.
• Sleep apnea notifications are now included — a useful screening feature given how many people have undiagnosed sleep apnea.
• Sleep-stage tracking underreports deep sleep — Mike O'Brien recorded 45-55 minutes of deep sleep per night while reference devices showed 1.5-2.5 hours.

Apple Watch Series 9

Optical HR, ECG, temperature sensing, SpO2 (disabled on post-Jan-2024 US units), crash + fall detection, Emergency SOS. The most complete mainstream-smartwatch health suite for iPhone users.

• ECG app (FDA-cleared) + temperature sensing — full Apple health sensor suite.
• SpO2 (blood oxygen) disabled on US units sold after January 2024 due to the Masimo patent dispute — units sold before, and outside the US, retain it.
• Crash detection + fall detection + Emergency SOS — full Apple safety suite.
• Temperature sensing — wrist-temperature tracking for cycle tracking + overnight insights.
• Sleep tracking + sleep stages — solid wrist-based sleep monitoring via the Apple Health app.

Apple Watch SE 3

The full watchOS workout app, activity rings, automatic workout detection, and built-in GPS. Apple rates about 7 hours of GPS workout tracking. It is not a dedicated running watch — no dual-frequency GPS — but for everyday fitness it covers the essentials well.

• Full watchOS workout app, activity rings and automatic workout detection — everything expected of an Apple Watch.
• Built-in GPS rated for about 7 hours of workout tracking — DesFit found real-world endurance well beyond that claim.
• The Quantified Scientist rates the Apple Watch SE as a pretty good GPS tracker — accurate enough for everyday runs and rides.
• Not a dedicated running watch — no dual-frequency GPS and no deep training analytics; serious runners still look to Garmin or the Ultra 3.
• Crash detection, fall detection and Emergency SOS carry over — Mike O'Brien notes fall detection is 'among the best in the industry.'

Apple Watch Series 9

Full watchOS workout suite — multisport, custom workouts, heart-rate zones, race route, Training Load. Excellent for everyday fitness; dedicated athletes still lean Garmin/Coros for deeper analytics.

• Full watchOS workout suite — multisport, custom workouts, heart-rate zones, race route, pacer.
• Apple Fitness+ integration — guided workouts mirror to iPhone/iPad with on-watch metrics.
• Single-frequency GPS — accurate for everyday running; the dual-band GPS is reserved for the Ultra line.
• Ars Technica notes that despite the top-tier sensor array, the Apple Watch 'is still not the best fitness tracker' — dedicated athletes lean Garmin.
• 50m water resistance — pool + open-water swim tracking supported.

Apple Watch SE 3

Apple still rates the SE 3 at 18 hours of all-day battery, and that conservative number holds — but independent endurance tests stretched it to 37-41 hours of continuous wear depending on size. The genuine upgrade is fast charging: roughly 0-80% in 45 minutes, with a 15-minute top-up buying about 8 hours. A low-power mode reaches ~32 hours.

• Fast charging is new to the SE line — about 0-80% in 45 minutes, matching Apple's claim in testing.
• A 15-minute top-up buys roughly 8 hours of use — enough to rescue a sleep-tracking night.
• Endurance test: the 44mm SE 3 ran ~41 hours of continuous wear and the 40mm ~37-38 hours — far beyond Apple's conservative 18-hour rating.
• Still rated 18 hours — fast charging helps, but daily charging is the reality, and you may need a pre-bed top-up for sleep tracking.
• A low-power mode extends life to roughly 32 hours on a single charge.

Apple Watch Series 9

~18 hours normal use, 36 hours in Low Power Mode. Daily charging required. Fast USB-C charging — 0-80% in roughly 45 minutes.

• ~18 hours normal use — daily charging required. The familiar Apple Watch battery ceiling.
• 36 hours in Low Power Mode — extends battery for travel or overnight sleep tracking.
• Smaller 41mm model's battery is the weak point — Wired: Apple's smaller watches 'historically' have shorter battery life.
• Fast USB-C charging — 0-80% in roughly 45 minutes; quick top-up before bed enables overnight sleep tracking.
• Notebookcheck's review headline noted the Series 9 'lasts longer' than the Series 8 — modest efficiency gains from the S9 SiP.

Apple Watch SE 3

watchOS 26 on Apple's S10 chip — identical core performance to the Series 11 and Ultra 3, including double-tap and wrist-flick gestures. 64GB of storage. Apple Pay, the App Store and the full ecosystem are all here. The one hard limit: it works only with an iPhone.

• Same S10 chip as the Series 11 and Ultra 3 — TheJuan&Only confirms identical core performance across the lineup.
• Supports the S10-enabled gestures — double-tap and wrist-flick to dismiss notifications.
• 64GB of storage and the full App Store, Apple Pay, Find My and Siri — nothing core is cut from the experience.
• iPhone-only — like every Apple Watch, the SE 3 does not work with Android phones.
• TechRadar: it has 'the same fantastic chipset as the Ultra 3 and Series 11' — the SE 3 doesn't feel slow or cut-down in daily use.

Apple Watch Series 9

watchOS (updatable to watchOS 11+), on-device Siri, Apple Pay, App Store, deep iPhone + Apple Health integration. S9 SiP enables the Double Tap gesture. iOS-only.

• S9 SiP enables the Double Tap gesture — pinch index finger + thumb to control the watch one-handed.
• On-device Siri — faster responses, works without an internet connection for many requests including health queries.
• watchOS — updatable to watchOS 11+, App Store, Apple Pay, deep iPhone + Apple Health integration.
• Best-supported smartwatch — Ars Technica: 'the Apple Watch remains the best-equipped and widely supported smartwatch on the market.'
• iOS-only — no Android compatibility. Requires an iPhone.

Apple Watch SE 3

Crack-resistant Ion-X glass, now rated about 4x tougher than the SE 2, over an aluminum case. Water resistance is 50m (5 ATM) — fine for pool and open-water swimming.

• 50m (5 ATM) water resistance — rated for pool and open-water swimming.
• Crack-resistant Ion-X glass, now about 4x more crack- and scratch-resistant than the SE 2.
• DesFit notes Apple Watch aluminum models hold up well in practice — he has scratched only one across many Apple Watches going back to the Series 3.
• Not as scratch-hardened as the Series 11's ceramic-coated glass or the Ultra 3's sapphire — fine for everyday wear, not adventure abuse.

Apple Watch Series 9

50m water resistance + IP6X dust resistance. Ion-X glass (aluminum) or sapphire crystal (stainless steel). Crack-resistant — durable for daily wear, though not adventure-rated like the Ultra.

• 50m water resistance + IP6X dust resistance — pool + open-water swim rated.
• Ion-X glass (aluminum model) or sapphire crystal (stainless steel model) — display protection scales with the case material.
• Durable for daily wear — but not adventure-rated like the Apple Watch Ultra (no MIL-STD, no dive certification).
• Crack-resistant front crystal — Apple's standard mainstream-watch durability.

Apple Watch SE 3

Built-in GPS, Apple Pay via NFC, Bluetooth and Wi-Fi. An optional cellular model adds standalone connectivity for about $50 more. The SE 3 lacks the Series 11's second-generation ultra-wideband chip, so it can only ping a lost iPhone rather than guide you to it.

• Built-in GPS, Apple Pay (NFC), Bluetooth and Wi-Fi — the standard Apple Watch connectivity set.
• An optional cellular model adds standalone connectivity for roughly $50 more — useful for leaving the phone behind.
• No second-generation ultra-wideband chip — the SE 3 can only beep a lost iPhone, not precision-guide you to it like the Series 11.

Apple Watch Series 9

GPS standard; optional LTE/eSIM (+$100). Second-gen Ultra Wideband chip for Precision Finding, NFC for Apple Pay, Bluetooth 5.3, Wi-Fi.

• Optional LTE/eSIM — Notebookcheck notes 'an additional $100 is charged for the eSIM function.'
• Second-generation Ultra Wideband chip — Precision Finding to locate a paired iPhone 15 with directional guidance.
• Single-frequency GPS — accurate for everyday tracking; dual-band is Ultra-only.
• NFC for Apple Pay + Bluetooth 5.3 + Wi-Fi — full smartwatch connectivity stack.

Apple Watch SE 3

At a held-steady $249, the SE 3 is the cheapest way into a current Apple Watch and the obvious pick for most iPhone owners. The $399 Series 11 adds ECG, blood oxygen, hypertension alerts, a brighter screen and 24-hour battery; the $799 Ultra 3 adds far more. For the majority, the SE 3's gaps will not be felt.

• TechRadar's verdict: the SE 3 'might be the best-value Apple Watch ever made.'
• Mike O'Brien calls it 'the best Apple Watch for most people' — major improvements with very few noticeable differences from the $400 Series 11.
• Gizmodo: 'The Apple Watch SE 3 is a stupidly good value for $250.'
• Step up to the $399 Series 11 for ECG, blood oxygen, hypertension alerts, a 2,000-nit screen and 24-hour battery — worth it only if you actually need those.
• Best for: first-time Apple Watch buyers and anyone who wants the core experience for the lowest price — Tom's Guide names the SE 3 'the best value, great for first-time users.'

Apple Watch Series 9

$399 (41mm) / $429 (45mm) launch. Now superseded by the Series 10 + 11 — a strong value if discounted. Competes with the Galaxy Watch and (for iOS) the Apple Watch SE.

• $399 (41mm) / $429 (45mm) launch price — standard mainstream Apple Watch pricing; +$100 for cellular.
• Now superseded by the Series 10 + 11 — TechRadar + Digital Trends both walk through whether to buy the Series 9 discounted or step up.
• GSMArena user reports buying the Series 9 'brand new at $359' — heavily discounted post-launch, a strong value at that price.
• vs Apple Watch SE: the Series 9 adds the always-on display, ECG, temperature sensing, and the brighter 2,000-nit screen. The SE is the budget pick.
• Best for: iPhone users who want a full-featured mainstream Apple Watch with ECG + always-on display + Double Tap, and find the Series 9 discounted now that the Series 10/11 have launched.