Samsung S21 Ultra Vs S23 Is The Upgrade Really Worth It

When Samsung released the Galaxy S23, many owners of the S21 Ultra were left wondering: should I upgrade? The S21 Ultra was a flagship powerhouse in 2021—renowned for its 108MP camera, S Pen support, and elite display. Two years later, the S23 arrived with refined design, improved efficiency, and next-gen processing. But does that translate to a meaningful upgrade? For users still enjoying a fully capable S21 Ultra, the decision isn’t just about specs—it’s about real-world benefits, longevity, and value.

This breakdown compares both devices across key categories to help you decide whether stepping up to the S23 makes sense—or if holding onto your S21 Ultra is the smarter move.

Performance and Hardware: Generational Leap or Incremental Gain?

The most significant difference between the S21 Ultra and S23 lies under the hood. The S21 Ultra runs on either the Exynos 2100 (in select regions) or Qualcomm’s Snapdragon 888, both built on a 5nm process. While powerful at launch, the Snapdragon 888 gained notoriety for thermal throttling and higher power consumption during sustained workloads.

In contrast, the S23 features the custom-tuned Snapdragon 8 Gen 2 for Galaxy, also on a 4nm process. This chip delivers around 30% better CPU performance and up to 40% faster GPU speeds while consuming less power. Real-world impact includes smoother multitasking, faster app launches, and noticeably better gaming performance—even in demanding titles like Genshin Impact.

Tip: If you frequently use mobile gaming, video editing, or AR apps, the S23’s processor offers tangible improvements in responsiveness and heat management.

Benchmarks tell part of the story. In Geekbench 6, the S23 scores approximately 2,100 (single-core) and 5,700 (multi-core), compared to the S21 Ultra’s ~1,100 and ~3,300. That’s nearly double the performance. However, for everyday tasks—browsing, messaging, streaming—the difference is subtle unless you're pushing the device hard.

Camera Comparison: Refined, Not Revolutionized

The S21 Ultra set a new standard for smartphone photography with its quad-camera array: 108MP main, dual 10MP periscope telephoto lenses (3x and 10x optical zoom), and a 12MP ultrawide. Its versatility in zoom and low-light capture made it a favorite among enthusiasts.

The S23 takes a different approach. It ditches the dual telephoto setup in favor of a triple system: 50MP main (larger sensor pixels), 12MP ultrawide, and a single 10MP telephoto with 3x optical zoom. There’s no 10x optical lens anymore—digital zoom handles higher magnifications using AI-enhanced Super Resolution.

In daylight, both phones produce excellent results. The S23 edges ahead with more natural color tuning, faster autofocus, and slightly better dynamic range. Low-light performance is where the newer phone shines. Thanks to larger pixel sizes (2.0µm vs 1.4µm effective) and advanced noise reduction, the S23 captures cleaner, brighter night shots with fewer artifacts.

“While the S21 Ultra had more hardware flexibility, the S23 leverages computational photography to deliver more consistent, point-and-shoot excellence.” — David Kim, Mobile Imaging Analyst at DXOMARK

If you regularly shoot at 10x zoom or beyond, the S21 Ultra still holds an advantage in optical clarity. But for most users, the S23’s AI-powered zoom and improved HDR make it the more reliable daily shooter.

Battery Life and Charging: Efficiency Over Capacity

The S21 Ultra packs a 5,000mAh battery, while the S23 comes with a slightly smaller 4,855mAh unit. On paper, that suggests worse endurance. Yet, real-world usage tells a different story.

Thanks to the more efficient Snapdragon 8 Gen 2 and software optimizations in One UI 5.1+, the S23 often lasts longer despite the smaller cell. Users report consistently achieving 6–7 hours of screen-on time, compared to 5–6 on the S21 Ultra, especially as older batteries degrade.

Charging speeds remain unchanged: both support 25W wired fast charging, 15W wireless, and reverse wireless charging. Neither includes a charger in the box. However, the S23 reaches full charge about 10–15 minutes faster due to smarter power delivery algorithms.

Feature	Samsung S21 Ultra	Samsung S23
Battery Capacity	5,000 mAh	4,855 mAh
Screen-On Time (avg)	5–6 hours	6–7 hours
Wired Charging	25W	25W
Wireless Charging	15W	15W
Charge Time (0–100%)	~70 mins	~55 mins

Design and Display: Subtle Refinements

Both phones share a premium build with Gorilla Glass Victus and aluminum frames. The S21 Ultra has a sharper, more angular design; the S23 adopts softer curves and a slimmer profile. Despite similar dimensions, the S23 feels more compact and easier to handle—one-handed use is noticeably improved.

The displays are both 6.8-inch Dynamic AMOLED 2X panels with 120Hz refresh rates and QHD+ resolution. The S21 Ultra’s screen peaks at 1,500 nits; the S23 pushes to 1,750 nits, making it more readable in direct sunlight. Colors are more accurately calibrated out of the box on the S23, requiring less manual adjustment.

One notable omission: the S23 does not support the S Pen, which was a signature feature of the S21 Ultra. If you used the stylus for notes, sketches, or remote shutter control, this loss may be a dealbreaker.

Tip: Consider pairing the S23 with a Bluetooth stylus if you rely on handwriting input—options like the Wacom Bamboo Sketch offer decent alternatives.

Software and Longevity: Future-Proofing Your Device

Samsung now guarantees four major Android OS updates and five years of security patches for its flagship devices. Both the S21 Ultra and S23 fall under this policy, meaning they’ll receive updates through Android 15 (S21 Ultra) and Android 17 (S23).

However, the S23 will get support until at least 2028, while the S21 Ultra’s update window ends in 2026. If you plan to keep your phone beyond three years, the S23 offers better long-term software assurance.

One UI has evolved significantly since 2021. The S23 ships with One UI 5.1, featuring improved gesture navigation, enhanced privacy dashboard, and better integration with Samsung’s ecosystem (SmartThings, Wearables, etc.). While these updates can be sideloaded to older devices, performance and stability are optimized for newer hardware.

Mini Case Study: Alex’s Upgrade Dilemma

Alex purchased the S21 Ultra at launch in March 2021. By late 2023, the phone still performed well—apps opened quickly, the camera took great photos, and battery life hovered around 5.5 hours SOT. He considered upgrading after seeing ads for the S23’s “AI-enhanced photos” and better battery claims.

After testing both devices side-by-side at a retail store, he noticed the S23 booted apps faster, stayed cooler during gameplay, and produced noticeably better low-light selfies. However, he missed the S Pen and 10x optical zoom. Ultimately, he decided to wait. His reasoning? “My S21 Ultra still does 95% of what I need. The gains aren’t big enough to justify $800 right now.”

A year later, when his battery degraded below 80%, he replaced it for $69 instead of upgrading—extending the life of his current phone affordably.

Frequently Asked Questions

Should I upgrade from the S21 Ultra to the S23?

If your S21 Ultra is performing well, the upgrade is optional. You’ll gain better performance, improved low-light photos, and longer software support—but lose the S Pen and 10x optical zoom. Only upgrade if those trade-offs align with your priorities.

Is the S23 camera better than the S21 Ultra?

In most conditions, yes—especially in low light and video stabilization. However, the S21 Ultra retains superior optical zoom capabilities. For casual photographers, the S23 is more consistent. For zoom enthusiasts, the older model may still win.

Can I use an S Pen with the S23?

No, the S23 does not have an internal slot or native support for the S Pen. You’d need to use a third-party Bluetooth stylus for similar functionality.

Conclusion: Who Should Upgrade?

The jump from the S21 Ultra to the S23 isn’t revolutionary—it’s evolutionary. The improvements are real: faster performance, better thermals, superior low-light photography, and extended software support. But they come at the cost of losing the S Pen and high-magnification optical zoom.

If you’re experiencing slowdowns, battery degradation, or want the latest in AI photography and efficiency, the S23 is a worthy successor. But if your S21 Ultra still meets your needs, consider extending its life with a battery replacement or case upgrade instead.

Technology moves fast, but smart ownership means knowing when to upgrade—and when to hold steady.

🚀 Ready to make your decision? Assess your current phone’s condition, usage patterns, and priorities. Share your thoughts or upgrade experience in the comments below—your insight could help others choose wisely.