Amazfit T-Rex 3 vs OnePlus Watch 3

Amazfit T-Rex 3

1.5-inch AMOLED, 480×480 resolution. Bright, vivid, with always-on support. Readable outdoors — a strong display for the price tier.

• 1.5-inch AMOLED, 480×480 resolution — bright, sharp, and vivid for an outdoor watch.
• Always-on display supported — informative without raising the wrist; the huge battery absorbs the cost.
• Readable in daylight — adequate brightness for outdoor workouts and navigation.
• A strong display for the price — AMOLED quality usually reserved for pricier watches.

OnePlus Watch 3

A 1.5-inch LTPO AMOLED at 466 x 466, now peaking at 2,200 nits — a clear brightness upgrade over the Watch 2 that makes it noticeably more readable outdoors. Sapphire crystal protects it.

• 1.5-inch LTPO AMOLED at 2,200 nits — The Verge notes it's larger and brighter than the Watch 2, with smaller bezels.
• The 2,200-nit brightness is noticeably more readable outdoors in direct sunlight than the Watch 2's panel.
• A new video watch face lets you upload your own clips — a fun, distinctive touch.
• Sapphire crystal protection — premium scratch resistance for the price.

Amazfit T-Rex 3

BioTracker optical HR, SpO2, sleep tracking, stress monitoring, readiness score. Covers everyday wellness; analytics aren't as deep as Garmin's.

• BioTracker optical HR — solid everyday heart-rate tracking; like all wrist sensors, less accurate than a chest strap for intervals.
• SpO2 (blood oxygen) — on-demand readings, useful for altitude on mountain adventures.
• Sleep tracking + stress monitoring + readiness score — Zepp's wellness suite covers the everyday basics.
• Health analytics aren't as deep as Garmin's — adequate for fitness, but no Endurance/Hill Score equivalent.
• Zepp Aura AI wellness features — sleep and readiness insights through the Zepp app.

OnePlus Watch 3

The OnePlus Watch 3 covers the basics — heart rate, SpO2, skin temperature, sleep, stress — plus a handy 60-second multi-metric Health Check. But health-tracking depth lags Google and Samsung, accuracy is middling, and the ECG hardware is disabled in the US for lack of FDA clearance.

• A 60-second Health Check captures heart rate, SpO2, ECG-style and arterial-stiffness metrics in one quick reading.
• No ECG in the US — the hardware is built in, but without FDA clearance the ECG Analyzer is disabled for US buyers.
• Heart-rate accuracy is improved over the Watch 2 but still imperfect — The Quantified Scientist found it picks up peaks reasonably and was positively surprised by outdoor cycling.
• Sleep-stage tracking is weak — The Quantified Scientist measured roughly 60% deep-sleep agreement and only ~36% REM agreement.
• Health-tracking depth lags rivals — OnePlus's OHealth app is functional but behind Google's Fitbit and Samsung Health.

Amazfit T-Rex 3

170+ sport modes, dual-band GPS, free offline maps with turn-by-turn navigation. Strong everyday and outdoor fitness coverage at the price.

• 170+ sport modes — an extensive activity library covering running, trail, cycling, swimming, hiking, and more.
• Free offline maps with turn-by-turn navigation — a feature set usually found only on pricier watches.
• Dual-band GPS — accurate tracking for running, trail, and outdoor adventure.
• Route import + breadcrumb navigation — load GPX routes for trail running and hiking.
• 10 ATM water resistance — pool, open-water, and high-pressure water activities supported.

OnePlus Watch 3

100+ workout modes with dual-frequency GPS and automatic detection. It's a capable everyday fitness watch — GPS accuracy is decent if not class-leading — and the huge battery means it can track multi-day adventures without an anxious eye on the charger.

• Dual-frequency (L1 + L5) GPS — Matt LeGrand found running accuracy decent, if not quite at the level of an Apple Watch Ultra.
• 100+ workout modes, including skiing with slope-angle tracking and swimming thanks to the 5 ATM rating.
• The huge battery is a real fitness advantage — a multi-day snowboarding trip with constant tracking still left the watch going strong.
• It's a capable everyday fitness watch, but serious athletes still note Garmin's deeper training analytics.
• 5 ATM water resistance covers pool and open-water swimming.

Amazfit T-Rex 3

Up to 27 days typical use, ~13 days under heavy use, ~42 hours of dual-band GPS. An enormous battery — a defining advantage at the price.

• Up to 27 days typical-use battery — an enormous figure that defines the T-Rex 3's value.
• ~13 days under heavy use — even with GPS workouts and AOD, the watch lasts well over a week.
• ~42 hours of dual-band GPS — supports multi-day ultra and adventure tracking without recharge.
• Magnetic charging clip — standard Amazfit charger; no Qi wireless charging.
• Battery endurance rivals Garmin's at a third of the price — a core T-Rex 3 advantage.

OnePlus Watch 3

The OnePlus Watch 3's defining strength. A 631mAh silicon-carbon battery and a dual-chip architecture deliver a genuine 5 days of full smartwatch use — unmatched in Wear OS — and up to 16 days in power-saver mode. Fast charging adds a full day in about 10 minutes.

• A genuine 5 days of full smartwatch use — Mark Ellis confirms the 5-day claim is 'pretty much bang on.'
• OnePlus's dual-chip architecture — a Wear OS chip plus a low-power RTOS chip — is the secret to the endurance, and nothing else in Wear OS matches it.
• Heavy use brings it down — a multi-day snowboarding trip with constant tracking landed closer to 3-4 days.
• Power-saver mode pushes battery to up to 16 days while still delivering notifications and tracking.
• Fast charging is excellent — about 10 minutes on the dock returns a full day of use, and a full charge takes roughly 45 minutes.

Amazfit T-Rex 3

Zepp OS 4 + Zepp app. Built-in speaker + microphone for Bluetooth calls. Works with iOS + Android. Regular firmware updates. Smaller app ecosystem than Wear OS.

• Zepp OS 4 — a steadily improving platform; Notebookcheck documents regular feature-adding firmware updates.
• Built-in speaker + microphone — Bluetooth calls and a voice assistant on the wrist.
• Zepp OS app ecosystem is much smaller than Wear OS — fine for fitness, maps, and notifications, limiting for app variety.
• Works with both iOS and Android via the Zepp app — cross-platform.
• Zepp app + ecosystem polish trails the big brands — adequate, but not as refined as Apple Health or Garmin Connect.

OnePlus Watch 3

Full Wear OS 5 with Google's app ecosystem and Google Wallet, layered with OnePlus's interface and the OHealth companion app. Performance is fast, though there's occasional lag — and the OHealth app is the weak link versus Google and Samsung.

• Full Wear OS 5 with the Google Play app ecosystem and Google Wallet — the complete Android smartwatch experience.
• Performance is fast and fluid — Android Police reports 'absolutely no problem' with everyday navigation.
• The OHealth companion app is the weak link — owners switching from Samsung find it behind the Wear and Samsung Health apps.
• Occasional system lag — some owners notice stutters when quickly exiting the always-on display into an app.
• It's Android-only — like every Wear OS watch, the OnePlus Watch 3 does not pair with an iPhone.

Amazfit T-Rex 3

MIL-STD-810H rugged build + 10 ATM water resistance. Polycarbonate case with a protective convex display. Built to survive serious outdoor abuse.

• MIL-STD-810H rugged build — validated against drop, shock, humidity, and temperature extremes.
• 10 ATM (100m) water resistance — pool, open-water, and high-pressure water activities.
• Protective convex display — the raised bezel shields the screen from impacts during outdoor use.
• Polycarbonate case — genuinely durable and lightweight, though it lacks the premium feel of a metal Garmin.

OnePlus Watch 3

A stainless-steel case with a titanium bezel and sapphire-crystal glass, rated 5 ATM and IP68. It's a genuinely rugged build for the price — one reviewer put it through a full multi-day snowboarding trip without issue.

• Stainless-steel case with a titanium bezel and sapphire-crystal glass — a genuinely premium, durable build.
• 5 ATM water resistance plus IP68 — fine for swimming, showering and rain.
• It held up to a full multi-day snowboarding stress test without issue — durable enough for outdoor adventures.

Amazfit T-Rex 3

Dual-band GPS (multi-constellation), free offline maps, Bluetooth, Wi-Fi. No LTE — calls route via Bluetooth to a connected phone.

• Dual-band, multi-constellation GPS — accurate tracking in urban canyons and dense tree cover.
• Free offline maps — full maps loaded onto the watch at no extra cost, with turn-by-turn navigation.
• Bluetooth + Wi-Fi — Bluetooth calls route through a connected phone; Wi-Fi for sync.
• No LTE — phone required for full connectivity; no standalone cellular.
• No NFC contactless payments in most regions — a connectivity gap vs Wear OS / Apple Watch.

OnePlus Watch 3

Dual-frequency GPS, Bluetooth, Wi-Fi and Google Wallet via NFC. The notable omission is cellular — there is no LTE model, so the OnePlus Watch 3 can't operate fully standalone.

• Dual-frequency (L1 + L5) GPS, Bluetooth, Wi-Fi and Google Wallet — the standard Wear OS connectivity set.
• No LTE model — the OnePlus Watch 3 is Bluetooth-only, so it can't go fully standalone away from a phone.
• Google Wallet handles contactless payments, and notifications and calls work well over Bluetooth.

Amazfit T-Rex 3

Around $280 launch. The value disruptor in the rugged-adventure category. Competes with the Garmin Instinct/Fenix and the Apple Watch Ultra — at a fraction of their price.

• Around $280 launch — Digital Trends confirms the $280 US price across colorways.
• Notebookcheck's framing: 'Cheaper than Garmin: Top smartwatch gets even better' — the value positioning is the headline.
• vs Garmin Instinct/Fenix: the T-Rex 3 wins decisively on price + battery + AMOLED; Garmin wins on training-science depth and metal-build prestige.
• vs Apple Watch Ultra: the Ultra is 3× the price; the T-Rex 3 delivers most of the rugged-outdoor feature set for a fraction of the cost.
• Best for: anyone who wants Garmin-Fenix-style ruggedness, free maps, and multi-week battery at roughly a third of the price — and doesn't need the deepest training analytics or a Wear OS app catalog.

OnePlus Watch 3

The OnePlus Watch 3 launched at $329.99, then took a confusing hike to $499.99, and now typically sells around $349.99. At its sale price it's a standout value; at full list it's harder to justify. It beats the Pixel Watch 4 and Galaxy Watch 8 decisively on battery, but trails them on software polish and health depth.

• CNET's verdict: the OnePlus Watch 3 has 'the best battery life of any Android smartwatch.'
• The pricing is confusing — it launched at $329.99, then jumped to $499.99; Digital Trends openly asks whether it's still worth buying at the higher price.
• Two months on, TechRadar says OnePlus fixed its biggest issue via updates and 'now I can recommend it to everybody.'
• vs the Pixel Watch 4 / Galaxy Watch 8: the OnePlus wins decisively on battery and build for the price; the others win on software polish and health-tracking depth.
• Best for: Android users who want the longest-lasting Wear OS watch in a premium build — and don't need ECG or a small case.