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Head to head

Samsung Galaxy Watch Ultra2 47mmvsSamsung Galaxy Watch9 40mm

Released
2026-08-07Samsung Newsroom UK — Galaxy Watch Ultra2 and Watch9, retrieved 2026-09-13
Price
£649Samsung Newsroom UK — Galaxy Watch Ultra2 and Watch9, retrieved 2026-09-22
Security updates until
Not published by the makerSamsung UK — How to update software on Galaxy Watch, retrieved 2026-09-13
Released
2026-08-07Samsung Newsroom UK — Galaxy Watch Ultra2 and Watch9, retrieved 2026-09-13
Price
£349Samsung UK store — Galaxy Watch9, retrieved 2026-09-13
Security updates until
Not published by the makerSamsung UK — How to update software on Galaxy Watch, retrieved 2026-09-13

2 wins for Galaxy Watch Ultra2 47mm1 win for Galaxy Watch9 40mm0 differences you won’t notice£300 apart at RRP

Verdict: Galaxy Watch Ultra2 47mm ahead on 2 rows, Galaxy Watch9 40mm on 1 row

On the makers’ published figures, the Galaxy Watch Ultra2 47mm wins on peak brightness (5,000 nits against 3,000 nits) and battery life (maker's claim) (80 h against 40 h); the Galaxy Watch9 40mm wins on weight (case only) (31.5 g against 61.5 g). The other 27 rows have no threshold or no direction to judge by, so nobody wins them.

True to scale

Galaxy Watch Ultra2 47mm · 47.4 × 47.1 mmGalaxy Watch9 40mm · 42.7 × 40.4 mm

Case outlines from each maker’s published dimensions, drawn to scale. A round case is an ellipse at those figures.

Specifications

A win is marked only where the figures can be ranked and the gap is one you could notice on the wrist. A row the site has no threshold for says whether the two differ, and that it is not ranking them. = marks the same figure on both, ≠ not ranked a difference with no ranking. Every figure carries its source.

Body

SpecificationSamsung Galaxy Watch Ultra2 47mmSamsung Galaxy Watch9 40mm
DimensionsDiffers, but not ranked.
47.4 x 47.1 x 10.7 mmOfficial
42.7 x 40.4 x 8.6 mmOfficial
Case size
47mmOfficial
40mmOfficial
Case shapeSame.
roundOfficial
roundOfficial
Weight (case only)
61.5gOfficial
31.5gOfficialwins this row

Galaxy Watch9 40mm is ahead here, by a gap you’d notice.

Case materialDiffers, but not ranked.
TitaniumOfficial
Armor AluminiumOfficial
Water ratingDiffers, but not ranked.
10 ATM, IP69K, MIL-STD-810H, EN13319Official
5 ATM + IP68 / MIL-STD-810HOfficial

Display

SpecificationSamsung Galaxy Watch Ultra2 47mmSamsung Galaxy Watch9 40mm
Display typeSame.
Super AMOLED, Full Colour Always On DisplayOfficial
Super AMOLED, Full Colour Always On DisplayOfficial
Display sizeDiffers, but not ranked.
1.52inOfficial
1.34inOfficial
ResolutionDiffers, but not ranked.
498 x 498Official
438 x 438Official
Peak brightness
5000nitsOfficialwins this row
3000nitsOfficial

Galaxy Watch Ultra2 47mm is ahead here, by a gap you’d notice.

Always-on displaySame.
YesOfficial
YesOfficial

Platform

SpecificationSamsung Galaxy Watch Ultra2 47mmSamsung Galaxy Watch9 40mm
Operating systemSame.
Wear OS 7Official
Wear OS 7Official
ChipSame.
Qualcomm SDW6100 (Snapdragon Wear Elite, 3nm, 5 core)Official
Qualcomm SDW6100 (Snapdragon Wear Elite, 3nm, 5 core)Official
StorageDiffers, but not ranked.
64GBOfficial
32GBOfficial
RAMSame.
2GB3rd party
2GB3rd party

Battery

SpecificationSamsung Galaxy Watch Ultra2 47mmSamsung Galaxy Watch9 40mm
Battery life (maker's claim)
80hOfficialwins this row
40hOfficial

Galaxy Watch Ultra2 47mm is ahead here, by a gap you’d notice.

Battery capacity
800mAh3rd party
No verified data
ChargingDiffers, but not ranked.
Fast Charging, up to 40% in around 30 minutesOfficial
Fast ChargingOfficial

Health

SpecificationSamsung Galaxy Watch Ultra2 47mmSamsung Galaxy Watch9 40mm
SensorsSame.
Accelerometer, Barometer, Bioelectrical Impedance Analysis Sensor, Electrical Heart Sensor, Gyro Sensor, Geomagnetic Sensor, Light Sensor, Optical Heart Rate Sensor, Temperature SensorOfficial
Accelerometer, Barometer, Bioelectrical Impedance Analysis Sensor, Electrical Heart Sensor, Gyro Sensor, Geomagnetic Sensor, Light Sensor, Optical Heart Rate Sensor, Temperature SensorOfficial
ECGSame.
YesOfficial
YesOfficial
Skin temperatureSame.
YesOfficial
YesOfficial
GPSSame.
L1+L5 Dual-Frequency GPS (GPS, Glonass, Beidou, Galileo, QZSS)Official
L1+L5 Dual-Frequency GPS (GPS, Glonass, Beidou, Galileo, QZSS)Official

Connectivity

SpecificationSamsung Galaxy Watch Ultra2 47mmSamsung Galaxy Watch9 40mm
Cellular modelSame.
YesOfficial
YesOfficial
Cellular model priceDiffers, but not ranked.
£649Official
£399Official
UK networks with eSIMSame.
EE, Vodafone3rd party
EE, Vodafone3rd party
Wi-FiSame.
802.11a/b/g/n 2.4GHz+5GHzOfficial
802.11a/b/g/n 2.4GHz+5GHzOfficial
BluetoothSame.
6.0Official
6.0Official
NFC paymentsSame.
YesOfficial
YesOfficial

Compatibility

SpecificationSamsung Galaxy Watch Ultra2 47mmSamsung Galaxy Watch9 40mm
Works withSame.
Android 13.0 or higher and with more than 1.5GB of memoryOfficial
Android 13.0 or higher and with more than 1.5GB of memoryOfficial
CompatibilitySame.
Android; some features need a Samsung phoneOfficial
Android; some features need a Samsung phoneOfficial
5 attributes neither watch has a sourced figure for

Strap width · Display area · Charge to 80% · Blood oxygen · Blood pressure. Rows appear as sources are cited — a gap in our data, not a statement about either watch.

The pairs a buyer of either watch would also weigh. Any two watches in the catalogue can be compared from the chooser.