Samsung Galaxy S25 vs Galaxy S23: How do they stack up?

Samsung's annual flagship smartphone upgrades have become notoriously iterative, even more so now that so many headline upgrades are focused on AI features that typically end up on older models anyway. Of course, as small as they seem year on year, those iterations add up so someone using an S21 might be tempted by the S25 after four years of upgrades, but it gets harder to recommend to those rocking anything newer than that. That includes the Galaxy S23. Back in 2023, we couldn't recommend the Galaxy S23 to S21 users and this year, it's a similar story for S23 users thinking of upgrading to S25.

As far as hardware goes, the Galaxy S25 and the Galaxy S23 are almost identical. Samsung makes some loose promises about better quality snaps thanks to the S25’s next-gen post-processing ProVisual engine and clearer video at night thanks to its updated Snapdragon 8 Elite processor but before getting our hands on with the devices, it’s impossible to say whether those claims hold any water.

There are some bigger differences between the S25 Ultra and S23 Ultra’s camera systems (well, bigger by comparison.) The S25’s ultra-wide lens has been upgraded to a 50MP lens, an obvious step up from the S23’s 12MP ultra-wide lens. The periscope telephoto lens on the S25 has also been upgraded to a 50MP sensor, compared to the S23 Ultra’s 10MP periscope lens. That offers more detail at a glance but has the side effect of reducing the length of the optical zoom. The S23 Ultra’s 10MP periscope lens offers 10x optical zoom, whereas the S25 Ultra’s 50MP periscope lens offers half that, with a 5x optical zoom. To compensate, the S25 Ultra offers 10x Optical quality zoom; a function that takes a centre-crop of a 50MP 5x zoom, resulting in a 12.5MP crop of the 50MP photo. In effect, it’s a sort of simulated 10x optical zoom that achieves slightly better fidelity than the S23 Ultra’s 10MP telephoto lens could.

Lastly, the Galaxy S25 Ultra can record in 4K up to 120 frames per second, whereas 4K video on the S23 Ultra topped out at 60 frames per second.

The Galaxy S25 series will launch with a few exclusive Galaxy AI features: Now Brief and Seamless Actions Across Apps (SAAP.) Both features will be enabled by Samsung’s One UI 7.0 operating system update and what Samsung calls the Personal Data Engine, an isolated memory core that handles AI features related to personal information on-device. This data is also protected by Knox, Samsung’s patented mobile security platform.

Now Brief is an AI-powered summary of your upcoming day and full credit to Samsung, it does look pretty neat. The feature monitors your daily habits and provides an ever-evolving daily brief when you typically start your day; weather, meetings, pending missed calls and messages. You get the gist. There isn’t much advertised by Samsung that modern smartphones can’t already handle, but the promise is that Galaxy AI, and the power bump, will make those features more seamless.

Speaking of seamless, the other major exclusive feature is a little more nebulous. What Samsung calls ‘Seamless actions across apps,’ seems to be an advanced application of existing features that can link tasks between its Gemini-powered search engine and everyday Galaxy apps.

Samsung’s demonstrative video shows someone replying to a picky eater by asking Galaxy AI to “find a few Italian, pet-friendly restaurants with outdoor seating nearby and text the results to Luca.” It’s all a little pedantic for my liking. For the record, I asked Gemini about Italian pet-friendly restaurants nearby me. It suggested the most unfriendly Italian restaurant for pets you could imagine, like a very snooty, intimate and expensive Italian restaurant with no outdoor seating.

Another example used is YouTube and Notes, which show some promise. The general idea is that you can look up a video on YouTube, say for movie or holiday recommendations, and rather than watching that video all the way through, you can simply ask Gemini to transcribe the recommendations listed in your preferred notes app (if Gemini supports it.)

Search and Calendar is another interesting AI addition. It lets you ask Galaxy AI to find events and place them in your calendar ahead of time. The example given shows someone asking Galaxy AI to add all upcoming football games for a particular team to their calendar and voila! Samsung’s video uses what seems to be a fake football team so we’ll have to wait and see if you add every Sydney Swans match to your calendar once the feature is released.

It’s crazy to look back at the S23 and remember the discourse around the thickest and ugliest camera bumps, but even by 2023, Samsung had moved on from that heinous trend (Apple is still holding on, for some reason.) I bring this up because the Galaxy S22 to S23 transition was the last serious design overhaul, everything since has looked almost identical at a glance.

Sometimes, you’ve just got to have it in your hand to feel the difference. The Galaxy S25 series might be tougher overall, thanks to the new Titanium frame in the S25 Ultra and Armour Aluminum 2 frame in the S25 and S25 Plus (both the S23 and S23 Ultra shared the same Armour Aluminum frame,) but it's also thinner and lighter. 

At the low end, the S25 is 0.4mm thinner than the S23 and 6g lighter. In the premium range, the S25 Ultra is 0.7mm thinner and 16g lighter than the S23 Ultra. 

Both screens are significantly brighter this year, with 2600 peak nits brightness compared to the S23 series' 1750 peak nits brightness but the S25 Ultra is the only model with the updated Gorilla Glass Armour 2. The S25 and S25 Plus share the same Gorilla Glass Victus 2 screen of the S23 phones. 

Besides that, the other major aesthetic difference is the colours available. Here's a comparison of the colours available for each handset. 

The upgraded custom Snapdragon 8 Elite chipset found in every Galaxy S25 handset isn't a revolutionary upgrade on the Snapdragon 8 Gen 2 processor at the heart of the S23 series, but it does allow for a few neat performance boosts.

The most important of these upgrades for most people will be the improved battery life. Combined with bigger 4,000mAh and 5,000mAh batteries, the Snapdragon 8 Elite for Galaxy chipset promises up to 31 hours of video playback with the S25 Ultra and up to 29 hours of video playback with the Galaxy S25. That's an extra seven hours when compared to the S23 (up to 22 hours) and an extra five hours when compared to the Galaxy S23 Ultra (up to 26 hours.)

As for the sheer processing power of the Galaxy S25 series, we'll have to wait to get our hands on the device before offering any meaningful commentary on its performance. On paper, Samsung boasts a 40% increase in NPU (neural processing unit) performance, a 37% boost in CPU performance and a 30% increase in GPU performance when compared to the S24 series, which houses an Exynos 2400 chipset in the S24 and S24+ and an upgrade Snapdragon 8 Gen 3 in the S24 Ultra (a revised version of the chipset inside the S23 series.)

One thing the S25 and S23 series have in common is a shared chipset amongst every handset. It doesn't matter if you get the cheapest S25 or the most expensive S25 Ultra, you'll get the same Snapdragon 8 Elite for Galaxy chipset. This choice was likely to create parity of Galaxy AI features across the devices in the new family.

Lastly, each Galaxy S25 handset will offer seven years of operating system and security updates so, technically, you could still be safely using the S25 in 2032 (which just doesn't seem like a real year) when you'll probably start eyeing off the Samsung Galaxy S32.