Oppo Watch S vs Samsung Galaxy Watch Ultra

Oppo Watch S

A 1.46-inch round AMOLED at 464 x 464 (317 ppi). It can hit a brilliant 3,000-nit peak — but only automatically, in Oppo's workout modes under strong sunlight. In everyday use it's capped at 600 nits, with a 1,500-nit high-brightness mode.

• 1.46-inch round AMOLED, 464 x 464 at 317 ppi — sharp and vibrant, with Splash Touch that keeps the screen usable when wet.
• The 3,000-nit peak is genuinely bright — but it only activates automatically in Oppo's workout modes when the watch detects strong sunlight.
• Everyday brightness is capped at 600 nits, with a 1,500-nit high-brightness mode — OPTechWithAskar notes that at the typical 600 nits 'this is just a normal good display.'
• In bright outdoor workouts the screen is excellent — you can read pace and heart rate without the wrist-tilt dance.

Samsung Galaxy Watch Ultra

Super AMOLED with Sapphire Crystal, 3,000 nits peak brightness — the brightest Galaxy Watch display. Always-on, with a red Night Mode for low-light readability.

• 3,000 nits peak brightness — the brightest Galaxy Watch display; excellent outdoor visibility.
• Sapphire Crystal display protection — premium scratch resistance suited to adventure use.
• Red Night Mode — turns watch faces red and black for night-vision-friendly readability.
• Always-on display supported — the large 590mAh battery absorbs the cost comfortably.
• Super AMOLED panel — vibrant and sharp; among the best smartwatch displays.

Oppo Watch S

For a budget watch the Oppo Watch S carries a serious sensor array — an 8-channel optical heart-rate sensor, a 16-channel SpO2 sensor, ECG electrodes and a skin-temperature sensor — anchored by a 60-second check that reads around 14 health indicators at once. ECG availability depends on regional certification.

• A serious sensor array — an 8-channel optical heart-rate sensor, a 16-channel optical SpO2 sensor, ECG electrodes and a wrist-temperature sensor.
• A 60-second health check measures around 14 indicators — heart rate, ECG, SpO2, vascular elasticity and more — in a single reading.
• On-demand ECG via a side-button electrode takes about 30 seconds — Oppo's ECG is certified as a class 2 medical device in China and in around 30 countries.
• ECG availability is region-dependent — it may be disabled depending on local certification where you buy the watch.
• Day-to-day it does continuous heart-rate monitoring with high/low alerts, all-day SpO2 and wrist-temperature trends, plus sleep stages and a sleep score.

Samsung Galaxy Watch Ultra

BioActive sensor — optical HR, ECG, BIA body composition, skin temperature, AGEs Index. DC Rainmaker found GPS very accurate; flagged Samsung HRV as out of alignment with other wearables.

• BioActive sensor — optical HR, ECG, BIA body composition, skin temperature, and the AGEs Index biological-age metric.
• DC Rainmaker's review title: 'Samsung Galaxy Watch Ultra: finally accurate' — HR and GPS accuracy markedly improved over earlier Galaxy Watches.
• DC Rainmaker flagged Samsung's HRV metrics as 'far out of alignment' with other wearables on most nights — a remaining sensor caveat.
• ECG + AGEs Index — clinical heart-rhythm checks plus biological-age estimation (both need a Samsung phone).
• Sleep tracking with sleep coaching — Samsung's detailed sleep-stage analysis and multi-week coaching program.

Oppo Watch S

The Oppo Watch S covers 100+ workout modes with built-in GPS and an AI sports coach that gauges readiness from HRV and recent training load. It's a capable everyday fitness tracker — though there's little independent accuracy testing to confirm how it stacks up.

• 100+ workout modes with built-in GPS, plus swim tracking thanks to the 5 ATM water rating.
• Oppo bills it as featuring an AI sports coach that analyzes readiness from HRV during sleep and your last 7 days of workouts.
• In workout modes the display ramps to its 3,000-nit peak — a real advantage for reading stats outdoors mid-exercise.
• Independent accuracy testing is limited — there is far less hands-on GPS and heart-rate validation than for flagship rivals.

Samsung Galaxy Watch Ultra

100+ workout modes, dual-frequency GPS, multisport mode, Energy Score, Race feature. Strong for an Android smartwatch; serious athletes still lean Garmin for training depth.

• Dual-frequency GPS — DC Rainmaker confirms 'very good GPS accuracy,' a real strength of the Watch Ultra.
• 100+ workout modes + multisport mode — broad activity coverage through Samsung Health.
• Energy Score + Galaxy AI Wellness Tips — Samsung Health's AI-powered daily readiness and guidance.
• Training analytics aren't as deep as Garmin's — DC Rainmaker still rates Garmin higher for serious endurance athletes.
• 10 ATM water resistance — pool, open-water, and high-pressure water activities supported.

Oppo Watch S

The Oppo Watch S's strongest card. Oppo rates the 330mAh battery at up to 10 days maximum, 7 days typical and about 4 days with the always-on display on — and fast charging adds a full day in 10 minutes, with a complete charge in roughly 75-90 minutes.

• Oppo rates the battery at up to 10 days maximum, 7 days typical, and about 4 days with the always-on display enabled.
• The Tech Shed confirms about 7 days for an active user doing regular GPS workouts, with the headline 10-day figure reserved for lighter use.
• With the always-on display on, real-world life drops to around 4 days — still competitive with most smartwatch rivals.
• Fast charging is excellent — a 10-minute top-up returns a full day of use.
• A full 0-100% charge takes roughly 75-90 minutes via the magnetic pin charger.

Samsung Galaxy Watch Ultra

590mAh battery — the largest in any Galaxy Watch. Up to ~60 hours typical use, ~100 hours in power-saving mode. Wireless fast charging. DC Rainmaker says it beats Apple's real-world battery.

• 590mAh battery — the largest in any Galaxy Watch; powers the Ultra's multi-day endurance.
• Up to ~100 hours in power-saving mode — DC Rainmaker calls the Ultra the best Wear OS watch 'if you need longer battery life.'
• DC Rainmaker: the Watch Ultra 'beats Apple's battery life in real-world usage, both in daily smartwatch mode and workout modes.'
• Wireless fast charging — a quick top-up before bed enables overnight sleep tracking.
• Still trails Garmin's multi-week endurance — but the Watch Ultra is the longest-lasting Wear OS option.

Oppo Watch S

The Oppo Watch S runs ColorOS Watch 7.1 on a power-efficient BES2800BP chip with 4GB of storage — not Wear OS. That choice is the reason the battery lasts a week, but it also means no Google Play app store and a simpler, more limited software experience.

• It runs ColorOS Watch 7.1 — a power-efficient platform that is the direct reason the battery lasts a week, not Wear OS.
• The trade-off is a simpler experience — there's no Google Play app store, so third-party app support is far more limited than on Wear OS.
• A power-efficient BES2800BP processor with 4GB of eMMC storage keeps the lightweight OS running smoothly.
• The companion health app works with both Android and iPhone — you don't need to own an Oppo phone to use the watch.

Samsung Galaxy Watch Ultra

Wear OS 5 + One UI 6 Watch + Galaxy AI. Full Wear OS app access, Samsung Health, Samsung Pay + Google Wallet. Best inside the Samsung phone ecosystem. Android-only.

• Wear OS 5 + One UI 6 Watch — DC Rainmaker highlights 'full access to the Wear OS platform' as a Watch Ultra strength.
• 3nm Exynos W1000 chip — fast, fluid performance; the same chip as the Galaxy Watch 7.
• Galaxy AI features — Energy Score, AI Wellness Tips, plus the full Google Play Store.
• Best inside the Samsung ecosystem — AGEs Index and ECG need a Samsung phone.
• Android-only — no iOS compatibility; best on a Samsung Galaxy phone.

Oppo Watch S

The Oppo Watch S is rated 5 ATM plus IP68 (and IP69), with Splash Touch that keeps the screen usable when wet. It's fine for swimming and everyday water — but Oppo specifically warns against hot showers, saunas and diving.

• 5 ATM water resistance plus IP68 and IP69 dust and water ratings — rated for swimming and everyday water exposure.
• Splash Touch keeps the touchscreen usable even when the watch is wet — handy after a swim or in the rain.
• Oppo specifically warns it's not meant for hot showers, saunas, hot springs or diving — and notes water resistance can reduce over time.

Samsung Galaxy Watch Ultra

Titanium case + Sapphire Crystal + 10 ATM water resistance + IP68 + MIL-STD-810H. Built for genuine adventure and underwater use.

• Titanium case — Samsung's most durable smartwatch material; built for adventure.
• 10 ATM water resistance + IP68 + MIL-STD-810H — the full rugged-adventure rating set.
• Sapphire Crystal display protection — highly scratch-resistant.
• Built for genuine adventure — the Watch Ultra is Samsung's answer to the rugged Apple Watch Ultra.

Oppo Watch S

Built-in GPS, Bluetooth, Wi-Fi and NFC cover the everyday essentials. There's no cellular model, so the Oppo Watch S relies on a paired phone for connectivity.

• Built-in GPS, Bluetooth, Wi-Fi and NFC — the standard everyday connectivity set.
• There's no cellular model — the Oppo Watch S relies on a paired phone for connectivity and can't go fully standalone.
• NFC supports contactless payments where the service is available.

Samsung Galaxy Watch Ultra

Dual-frequency GPS, LTE built in, NFC for Samsung Pay + Google Wallet, Bluetooth, Wi-Fi. Emergency siren for safety.

• Dual-frequency GPS — DC Rainmaker confirms 'very good GPS accuracy.'
• LTE built in — standalone calls, texts, and music streaming without the phone.
• Emergency siren — a loud audible alarm for emergency signaling, an Ultra-tier safety feature.
• NFC for Samsung Pay + Google Wallet — both contactless options.
• Bluetooth + Wi-Fi — full Wear OS connectivity stack.

Oppo Watch S

The Oppo Watch S launched at around $399 NZD (roughly $230 USD) and is not officially sold in the US. For the price it's a strong value — week-long battery, ECG, a premium-feeling build — as long as you accept the simpler ColorOS platform.

• The Tech Shed's verdict: 'the Oppo Watch S is one of the best value smartwatches I've ever tested.'
• It launched at around $399 NZD — roughly $230 USD — undercutting flagship smartwatches significantly.
• It's a niche device — Oppo doesn't officially sell wearables in the US, so availability and support are limited there.
• FutureFive frames it well — it focuses on design, health tracking and battery life rather than software complexity.
• Best for: anyone who wants a featherweight, week-lasting health smartwatch at a budget price and doesn't need a deep app ecosystem.

Samsung Galaxy Watch Ultra

$649 launch. Samsung's rugged flagship — competes with the Apple Watch Ultra (different platform) and Garmin. The longest-lasting, most durable Wear OS watch.

• $649 launch price — significantly more than a standard Galaxy Watch, justified by titanium, the bigger battery, and adventure features.
• DC Rainmaker: 'definitely the best Wear OS watch on the market today, if you need longer battery life, very good GPS accuracy, and full access to the Wear OS platform.'
• vs Apple Watch Ultra: different platforms — the Galaxy Watch Ultra is the Android adventure flagship, with the unavoidable visual resemblance.
• vs Garmin: Samsung wins on Wear OS apps + smart features; Garmin wins on training depth and even longer battery.
• Best for: Samsung phone owners who want the most durable, longest-lasting Wear OS watch with genuine adventure and dive features — and can look past the Apple resemblance.