Galaxy Watch8 40mm a 30 g Wear OS watch with a 3,000 nit screen

What is new about the Galaxy Watch8?

Samsung announced the Galaxy Watch8 on 9 July 2025 and it went on sale on 25 July, according to GSMArena. The headline change is the case. Samsung calls it a cushion design: a squared-off, brushed aluminium body with a round screen sitting on top, borrowed from the Galaxy Watch Ultra. It is also thinner, at 8.6 mm, which Samsung uses as its main design claim.

The screen is brighter too. Samsung quotes up to 3,000 nits, and GSMArena notes that the Watch7 peaked at 2,000 nits. Inside is a 3 nm, five-core processor (GSMArena identifies it as the Exynos W1000), 2 GB of memory and 32 GB of storage. Software is Wear OS with Samsung's One UI 8 Watch on top, and Google's Gemini assistant runs on the watch.

New health features include an Energy Score, Bedtime Guidance, a Running Coach, Vascular Load during sleep and an Antioxidant Index that reads a finger placed on the back of the watch. The older ECG, blood pressure and body composition tools remain.

How big is it, and how will it wear?

Samsung lists the 40 mm version at 42.7 mm tall, 40.4 mm wide and 8.6 mm deep, and 30 g without the strap. That is small and light by smartwatch standards, and it should suit wrists that find most smartwatches bulky. The screen is a 1.3 inch (34 mm) Super AMOLED at 438 by 438 pixels.

The strap fixes with Samsung's Dynamic Lug System, a quick-release clip rather than standard spring bars. GSMArena counts this as a downside, because ordinary watch straps will not fit without an adaptor. If you like changing straps, budget for Samsung's own or third-party bands made for the system.

What does the battery and tracking deliver?

The 40 mm model has a 325 mAh battery. Samsung quotes up to 40 hours with the always-on display off and up to 30 hours with it on. In practice that is a nightly or near-nightly charge, especially if you want sleep tracking.

Outlook Business found real use fell short of the estimate. With the always-on display off, its reviewer reached about 32 to 33 hours before needing to charge, and took to topping the watch up for 30 minutes twice a day. GSMArena's review lists battery life as under two days on both the Watch8 and Watch8 Classic.

Positioning is a strength. The watch supports dual-frequency GPS (L1 and L5) along with GLONASS, Galileo and BeiDou, which helps accuracy around tall buildings and trees. There is also an air pressure sensor, a skin temperature sensor and Samsung's BioActive sensor for heart rate, ECG and body composition.

How well is it built?

Samsung rates the case at 5 ATM and IP68 and says it meets the MIL-STD-810H durability standard, though that is a test of drops and temperature, not a guarantee of toughness. The frame is what Samsung calls Armor Aluminium, and GSMArena lists a sapphire crystal over the screen, which is unusual at this price and should resist scratches well. Swimming and showering are fine. Diving is not what it is for.

Will it work with my phone?

This is the big question. Samsung says the Watch8 must be paired with an Android 12 or newer phone, and the Galaxy Wearable app is not supported on iOS, so iPhone owners should look elsewhere. Some features go further and need a Samsung Galaxy phone: GSMArena notes that ECG, irregular heart rhythm alerts and blood pressure only work with Samsung handsets.

Is it good value against its rivals?

Samsung's UK store lists the 40 mm Bluetooth Watch8 at £269, the 44 mm version at £299 and the newer Galaxy Watch9 40 mm at £349. The Watch9 is the newer model, but the Watch8 already has the slim case, bright screen and Gemini support, so the £80 gap buys less than it might seem.

Outside Samsung, GSMArena points to the OnePlus Watch 3 for far longer battery life on Wear OS, and Huawei's Watch GT range if you can live without Google's apps. Both outlast the Watch8 between charges, but neither matches its health toolkit with a Samsung phone.

What is the catch?

Battery life is the main one. A watch that needs charging every day or so asks you to build a routine around it, and that is harder if you also want it to track your sleep. The proprietary strap fitting and the Samsung phone requirement for some health tools narrow its appeal further.

GSMArena also called the Watch8 a modest upgrade over the Watch7 at its launch price. At £269 that criticism carries less weight, but anyone with a working Watch7 has little reason to change.

“At £269 the Watch8 is the slim, bright Samsung watch to buy, as long as you charge it nightly.”

What do owners say?

Themes from public owner feedback, paraphrased. We never copy Amazon reviews or ratings.

• A long-term owner commenting on GSMArena's Watch8 and Watch8 Classic review says battery life improved after the first months and should stretch to about two days.

  GSMArena reader comments (opens in a new tab)

• An owner who upgraded from a Watch4 found the new watch smoother but struggled to find watch faces they liked.

  GSMArena user opinions (opens in a new tab)