Samsung Galaxy S25 Ultra vs Galaxy S23 Ultra: Is it worth upgrading to the 2025 flagship?

Samsung’s Galaxy S25 Ultra is here to take on the 2025 flagship market – but is it worth upgrading from the still-capable Galaxy S23 Ultra?
The Samsung Galaxy S25 Ultra boasts an all-new look that brings it more in line with the rest of the Galaxy S collection alongside upgrades to camera technology, processing power and charging speeds that allow it to better compete in the 2025 market.
However, despite its refreshed look, the Galaxy S23 Ultra is still a capable smartphone in its own regard, and one that matches the S25 Ultra in several key areas.
Whether you’re considering an upgrade or want to save a bit of cash on a flagship smartphone, here’s how the Samsung Galaxy S25 Ultra compares to the Samsung Galaxy S23 Ultra in everyday use.
Spec comparison
Pricing and availability
The Samsung Galaxy S25 Ultra starts at £1,249/$1,299 with 256GB of storage, though it’s available with up to 1TB of storage if 256- or 512GB isn’t enough for your needs. It’s available to buy right now from Samsung and third-party retailers following an early February 2025 launch.
The Galaxy S23 Ultra, having been released back in 2023, is now way more affordable than its £1,249/$1,199 launch RRP. It can be found at the likes of Amazon for as little as £679/$795, offering a healthy discount compared to its newer sibling.
Design
- Galaxy S23 Ultra has classic ‘Ultra’ design
- Galaxy S25 Ultra has flat edges and rounded corners
- Galaxy S25 Ultra is slightly more durable
The Samsung Galaxy S23 Ultra’s combination of curved edges and pointed corners was a staple of the top-end phone’s design for years, continuing with the S24 Ultra the following year, but the S25 Ultra has bucked the trend with an entirely new form factor.
We praised the S23 Ultra’s design when we reviewed the smartphone back in 2023, noting how the curved edges helped the extra-large phone sit more comfortably in the hand, though it did feel boxy compared to similarly-sized phones like the iPhone 14 Pro Max with those pronounced corners.
It also didn’t match the rest of the S23 collection, which adopted the more modern combination of rounded corners and flat edges.


The same can’t be said with the Galaxy S25 Ultra, however. Samsung has finally unified the design of the entire Galaxy S25 range with the Ultra model sporting the same rounded corners and flat edges as its siblings, making for a more premium look overall when compared to the S23 Ultra.
It also offers way better purchase on the flat sides than its curved sibling, though the older model is marginally more comfortable to hold as a result.
There are also minor tweaks to other areas of the design, including new bezels on the rear cameras on the S25 Ultra and the use of titanium in place of aluminium, but for the most part, it retains the core Galaxy DNA.
Both smartphones offer IP68 dust and water resistance to keep your phone safe during trips to the beach, though the S25 Ultra’s Gorilla Armor 2 glass protection is more durable than the S23 Ultra’s Gorilla Glass Victus 2.
Winner: Samsung Galaxy S25 Ultra
Screen
- Both offer AMOLED screens with 120Hz refresh rate and QHD resolution
- Galaxy S25 Ultra is 0.1 inches larger with slimmer bezels
- Galaxy S25 Ultra has an impressive anti-reflective coating
The core screen experience is pretty similar when comparing the two Galaxy flagships, with both offering Samsung’s impressive Dynamic AMOLED 2x screen tech with an LTPO-enabled 120Hz refresh rate and a pixel-packed QHD+ resolution – but there are subtle differences between the two.
That starts with the size of the screen; the S25 Ultra sports a 6.9-inch screen despite measuring in at similar dimensions to the S23 Ultra, thanks mainly to its ultra-slim bezels. Even compared to the S23 Ultra, these bezels are impressively thin, adding to the overall immersion and giving it an ultra-premium look.


The S25 Ultra is also the first Galaxy Ultra in quite some time to have an entirely flat display, compared to the curved edges on offer from the S23 Ultra. The S23 Ultra’s curvature isn’t egregious, but you’ll likely already have a preference on whether you like flat or curved screens better.
That does mean that swiping in from the sides of the screen is a little nicer on the curved S23 Ultra, however, compared to the slightly sharp sensation you’ll get from the S25 Ultra’s flat edges.
The anti-reflective coating of the S25 Ultra could be a dealbreaker for some though; we found the anti-reflective properties of the screen to be particularly impressive even when compared to similarly premium smartphones. The S25 Ultra doesn’t completely negate these reflections, of course, but it’s way less noticeable, even when reflecting a source of light like a lamp.
That said, regardless of the model of Ultra you have, you’ll be getting a top-tier screen experience with plenty of detail, vibrant colours and deep blacks, ideal for both scrolling through TikTok and playing games.
Winner: Samsung Galaxy S25 Ultra
Cameras
- Both feature 200MP main cameras
- S25 Ultra has better secondary cameras
- S25 Ultra offers Galaxy LOG video recording
Both Galaxy flagships offer impressive camera performance, with both featuring the same 200MP main camera that delivers consistently impressive shots in both well-lit and low-light scenarios, though there are differences on offer when it comes to the secondary camera setup.
The Galaxy S23 Ultra has a combination of telephoto lenses, offering 10MP 3x and 10x shooters to boost the phone’s zoom capabilities. We found the combination handy to close the gap, but the combination of low resolutions and narrow apertures meant they weren’t great once light levels began to drop.
There’s also a 12MP ultrawide that, like the telephoto lenses, offered great performance during the day but suffered in the evening with a lack of detail compared to the main sensor.


The S25 Ultra looks to ‘fix’ the secondary camera setup of its predecessor by ditching the 10MP 10x telephoto for a boosted 50MP 5x periscope lens. This helps the S25 Ultra provide better-quality shots between the 5-10x where the S23 Ultra struggled with its 3x sensor, while the periscope design of the lens means that performance is solid way beyond the 10x mark too.
Both are capable of those signature Samsung moon shots, but when it comes to shooting anything else, the S25 Ultra’s zoom lens delivers better results.
It’s a similar story with the upgraded 50MP ultrawide, the only real hardware change on offer from this year’s flagship, massively boosting the performance of the ultrawide sensor, especially when it comes to low-light photography.
The S25 Ultra also offers more advanced video capabilities including the ability to shoot in Galaxy LOG, though this is admittedly a rather niche feature that only dedicated videographers will dabble with.
Winner: Samsung Galaxy S25 Ultra
Performance
- Galaxy S25 Ultra boasts the Snapdragon 8 Elite
- Galaxy S23 Ultra features the Snapdragon 8 Gen 2
- Galaxy S25 Ultra is way faster than S23 Ultra
If there’s one area where the updated Samsung Galaxy S25 Ultra really pulls away from the S23 Ultra, it’s the performance department. We’re talking about an abnormally large jump in performance here, mainly down to the use of the Snapdragon 8 Elite for Galaxy.
It boasts the same Orion CPU architecture as its desktop-focused Snapdragon X Elite and offers around 40% better performance than the Snapdragon 8 Gen 3 for Galaxy – and even that was faster than the Snapdragon 8 Gen 2 for Galaxy found in the S23 Ultra.


Let’s get specific here; while the S23 Ultra scored 1489 and 4527 in Geekbench 6’s single- and multi-core tests respectively, the S25 Ultra managed 2886 and a whopping 9515. When it comes to more CPU-heavy tasks, the S25 Ultra has over double the power of the S23 Ultra.
It’s a similar story in the GPU department too, with the S23 Ultra scoring 3766 in the 3DMark Wildlife Extreme test while the S25 Ultra managed an impressive 6680.
In everyday use, it’s a little harder to tell the difference between the two devices. Both offer smooth, rapid everyday performance, though the S25 Ultra should load apps a little faster and offer better frame rates in demanding games. A larger vapour chamber allows the S25 Ultra to stay cooler than the S23 Ultra in longer gaming sessions too.
The 8 Elite also helps power the on-device AI experience – which we come to shortly.
Finally, the Galaxy S25 Ultra offers up to 16GB of RAM compared to the S23 Ultra’s 12GB, though both offer the same 256GB, 512GB or 1TB of storage.
Winner: Samsung Galaxy S25 Ultra
Software and AI
- S25 Ultra’s new Galaxy AI features are hit-and-miss
- S23 Ultra to get OneUI 7 update in coming months
- S25 Ultra has much better long-term software support
The Samsung Galaxy S23 Ultra originally shipped with OneUI 5 based on Android 13 before getting OneUI 6 sometime after the launch of the Galaxy S24 range last year.
We were a big fan of the software at the time, praising OneUI’s ease of use, though the amount of Samsung-branded apps was a little much, with several Google dupes that served very little purpose – something that hasn’t changed with subsequent OneUI releases, much to our reviewers’ chagrin.
The Galaxy S25 Ultra, on the other hand, ships with Samsung’s new and shiny OneUI 7 based on Android 15. It’s a more substantial update than recent iterations of Samsung’s UI, bringing with it redesigned icons, new animations, a new split quick control design and much more that our reviewer praised.


Then there’s Galaxy AI to consider. This year’s S25 Ultra brought with it new additions to the already wide roster of AI features including Now Brief, a smarter Gemini that can perform multi-app functions and new on-device AI processing capabilities.
However, in testing, we felt that the new AI features weren’t revolutionary, with the Now Brief’s limited information being a particular disappointment of ours. Despite Samsung’s claim of pulling information from various sources on your phone, our reviewer consistently only saw basic information like weather and calendar events.
Plus, with the S23 Ultra getting many of the S24 Ultra’s Galaxy AI features in the OneUI 6 software update, it’s possible that the S23 Ultra will gain many of the same AI capabilities when it receives the OneUI 7 update in the coming months – albeit likely cloud-based rather than on-device.
The Galaxy S25 Ultra excels when it comes to long-term support, however. The latest flagship is slated to get a whopping seven OS upgrades that’ll take it through to OneUI 14 based on Android 22, while the S23 Ultra only gets four OS upgrades.
Considering it has already had an upgrade to OneUI 6 and we’re awaiting the upgrade to OneUI 7, there are only two major OS upgrades left for the S23 Ultra – meaning it’ll stop getting OS upgrades in just a couple of years.
Winner: Samsung Galaxy S25 Ultra
Battery life
- Both phones feature a 5000mAh battery
- Both can last a day without complaint
- S25 Ultra charges faster despite same 45W charging
Despite the two-generation gap between the two smartphones, both the Galaxy S23 Ultra and Galaxy S25 Ultra offer the same combination of a 5000mAh battery and 45W fast charging.
With that in mind, it should come as no surprise that both smartphones offer similar battery longevity, with neither struggling to get us through an average day’s use in testing. That’s with power-sapping features like the QHD+ resolution active, for reference.
Neither is what we’d describe as a two-day device, however. The S25 Ultra finishes a full day with around 20-30% left in the tank, while the S23 Ultra wraps up with around 30-40%.


That said, Samsung has improved the efficiency of its 45W charging over the past few generations, as we found out in testing. The Galaxy S25 Ultra reached 70% charge in just 30 minutes of charging, compared to the 51% from the Galaxy S23 Ultra. It also achieved a full charge in 62 minutes, a whopping 29 minutes faster than its predecessor.
Both also come with the same 15W wireless charging support, though the newer S25 Ultra technically supports Qi 2.0 despite not offering built-in magnets – there are third-party cases for that instead.
Winner: Samsung Galaxy S25 Ultra
Final thoughts
The Samsung Galaxy S25 Ultra is clearly the more capable of the two phones, with a bigger screen, better cameras, way better performance, longer software promise and improved charging speeds – but is there really enough here to justify an upgrade from the S23 Ultra? I’m not so sure.
Yes, the S25 Ultra is technically more capable in most regards, but the S23 Ultra comes pretty close in key areas like display tech, cameras and battery life. That means the experience might not be as transformative as one might expect when moving from one to the other.
That said, if you’re on more of a budget, the discounted Galaxy S23 Ultra might serve your needs better.
For more smartphone inspiration, take a look at our selection of the best smartphones.