Samsung A51 Vs S9 Is The Newer Model Really An Upgrade

When Samsung released the Galaxy S9 in 2018, it set a high bar for flagship Android phones—excellent display, top-tier camera, and solid build quality. Fast forward to 2020, and the Galaxy A51 entered the market as a mid-range contender with modern features like a quad-camera setup and a sleek Infinity-O display. But is the A51 truly an upgrade over the older S9, despite being in a different price bracket? For users weighing options between these two models—whether upgrading from an S9 or choosing a budget-friendly alternative—the answer isn’t as straightforward as “newer equals better.” Let’s break down key aspects to see where each device excels and whether the A51 justifies its place as a successor in practical use.

Design and Build: Modern Aesthetics vs Premium Feel

The Galaxy S9 was built with premium materials: glass front and back with an aluminum frame, IP68 water and dust resistance, and a compact 5.8-inch form factor that fits comfortably in one hand. Its design felt luxurious and durable, a hallmark of Samsung’s flagship lineup at the time.

In contrast, the A51 adopts a more contemporary look with a plastic body and a larger 6.5-inch Super AMOLED display featuring a hole-punch front camera. While the screen-to-body ratio is higher and the overall aesthetic more modern, the polycarbonate build lacks the heft and refinement of the S9. The A51 also misses out on official IP rating, making it less resilient in wet conditions.

Tip: If you prioritize durability and water resistance, the S9 remains a stronger choice despite its age.

While the A51 feels lighter and more suited to extended use, especially for media consumption, the S9 delivers a more premium tactile experience. Design preferences will vary—some may favor the sleek minimalism of the S9, while others appreciate the larger, edge-to-edge screen of the A51.

Display Quality: Size vs Resolution and Brightness

Both phones feature Super AMOLED panels, which means vibrant colors, deep blacks, and excellent viewing angles. However, there are meaningful differences.

The S9’s 5.8-inch Quad HD+ (1440 x 2960) display offers sharper pixel density (570 PPI) and higher peak brightness, making it superior in direct sunlight and HDR content playback. It also supports HDR10, enhancing streaming quality on platforms like Netflix.

The A51 uses a larger 6.5-inch Full HD+ (1080 x 2400) panel with a lower pixel density (405 PPI). While still crisp for most users, the screen appears slightly softer when viewed up close. It lacks HDR support and doesn’t reach the same brightness levels, affecting outdoor visibility.

“Even years later, the S9’s display holds up against many mid-range devices thanks to its resolution and color accuracy.” — David Kim, Mobile Display Analyst at TechPulse

Performance: Flagship Chip vs Mid-Range Reality

Under the hood, the S9 runs on either the Qualcomm Snapdragon 845 or Exynos 9810, depending on region—both flagship-grade chips at launch. Even today, they handle everyday tasks, multitasking, and moderate gaming with ease. Paired with 4GB of RAM, the S9 delivers smooth performance with near-instant app launches and fluid animations.

The A51, powered by Samsung’s Exynos 9611 (a mid-range chipset), comes with 4GB or 6GB RAM options. While sufficient for social media, web browsing, and video streaming, it struggles with heavier apps and sustained gaming loads. Users report occasional stutters when switching between multiple apps or during prolonged use.

Storage is another consideration. The S9 launched with UFS 2.1 storage, faster than the eMMC 5.1 used in the A51. This translates to quicker file transfers, app installations, and system responsiveness—even after years of use.

Real-World Example: Daily Use After Two Years

Consider Maria, who upgraded from her aging S9 to an A51 in 2021. She expected improvements in battery life and camera features. While she appreciated the larger screen and longer battery, she noticed her banking app took longer to load, and Instagram would occasionally reload stories instead of caching them. “It felt like I stepped back in speed,” she said. “The S9 still opened apps faster, even though it was three years old.”

This case illustrates that raw specs don’t always reflect real-world experience. The S9’s hardware foundation gives it staying power that the A51’s mid-tier components can’t match.

Camera Comparison: More Lenses Don’t Always Mean Better Photos

The A51 touts a quad-camera array: 48MP main, 12MP ultra-wide, 5MP macro, and 5MP depth sensor. On paper, this seems like a massive leap over the S9’s single 12MP rear shooter. But megapixels and lens count aren’t everything.

The S9’s camera, though limited in quantity, benefits from larger pixels (1.4µm vs 0.8µm on the A51’s main sensor), dual-pixel autofocus, and advanced processing tuned for low-light performance. In dim environments, the S9 consistently produces cleaner, more detailed images with accurate colors and dynamic range.

The A51’s main sensor relies on pixel binning (combining four pixels into one 1.6µm super-pixel) to improve light capture, but results often appear oversharpened or overly processed. The ultra-wide lens adds versatility, but image quality drops noticeably at the edges. The macro and depth sensors are largely gimmicky, offering limited practical benefit.

For video, the S9 supports 4K at 60fps and Super Slow-mo at 960fps. The A51 only records 4K at 30fps and lacks advanced slow-motion modes. If you value video quality, the S9 remains superior.

“The S9’s camera software and sensor tuning were optimized over months. Many mid-range phones today still can’t replicate that balance.” — Lena Park, Mobile Photography Instructor

Battery and Software: Longevity vs Updates

Here, the A51 gains a clear advantage. With a 4000mAh battery compared to the S9’s 3000mAh, it easily lasts a full day—and often stretches into a second—with moderate use. The S9, while efficient, requires daily charging and struggles with heavy usage.

However, software support tells a different story. The S9 received updates up to Android 10 with One UI 2.0. The A51 launched with Android 10 and was eligible for two OS upgrades, reaching Android 12. Both are now beyond official support, but the A51 had a longer update window typical of Samsung’s A-series at the time.

Despite this, the S9’s near-stock Android experience (especially post-One UI refinements) feels cleaner and more responsive than the heavier skin on the A51, which can contribute to sluggishness over time.

Comparison Table: Samsung A51 vs S9 at a Glance

Feature	Samsung Galaxy S9	Samsung Galaxy A51
Release Year	2018	2020
Display	5.8\" QHD+ Super AMOLED, HDR10	6.5\" FHD+ Super AMOLED
Processor	Snapdragon 845 / Exynos 9810	Exynos 9611
Ram / Storage	4GB / 64GB (UFS 2.1)	4/6/8GB / 128GB (eMMC 5.1)
Rear Camera	12MP (f/1.5-2.4 variable aperture)	48MP + 12MP UW + 5MP Macro + 5MP Depth
Front Camera	8MP	32MP
Video Recording	4K@60fps, Super Slow-mo	4K@30fps
Battery	3000mAh	4000mAh
Water Resistance	IP68	None
OS Updates	Up to Android 10	Up to Android 12

Frequently Asked Questions

Is the Samsung A51 faster than the S9?

No. Despite being newer, the A51 uses a mid-range processor and slower storage, resulting in lower overall performance. The S9’s flagship chip ensures snappier response times and better multitasking.

Which phone has the better camera?

The S9 produces better photos in most conditions, especially low light. While the A51 offers more lenses, including ultra-wide and macro, the image quality, dynamic range, and video capabilities of the S9 are superior.

Should I buy an A51 if I have an S9?

Only if battery life and screen size are your top priorities. For performance, build quality, and camera consistency, sticking with or repairing an S9—or upgrading to a newer flagship—makes more sense.

Final Verdict: Newer Doesn’t Always Mean Better

The Samsung A51 brings some modern conveniences: a larger battery, bigger screen, and additional camera modes. But when evaluated holistically, it doesn’t surpass the Galaxy S9 in core areas like performance, display quality, camera excellence, or build integrity. The S9 remains a compelling device for users who value responsiveness, reliability, and photographic capability.

The takeaway? Technological progress isn’t linear across all segments. While newer phones often introduce flashy features, they sometimes compromise on fundamentals to hit lower price points. The A51 is a solid budget phone, but it isn’t an outright upgrade over a well-maintained S9.

🚀 Think twice before assuming newer is better. Evaluate what matters most—performance, camera, battery, durability—and choose based on real needs, not release dates. Share your experience: did you switch from an S9 to an A51? What surprised you?