Samsung A51 Vs A31 Is It Worth Upgrading Or Are They Basically The Same

When Samsung releases multiple phones in the same year under similar price brackets, it’s natural to wonder: are they really different, or just rebranded versions of each other? The Samsung Galaxy A51 and A31 sit close together in the mid-range lineup, both launched within months of each other in 2020. On paper, they look alike—similar designs, comparable software, and overlapping features. But for users deciding whether to upgrade from the A31 to the A51, or choosing between them secondhand today, the differences matter more than you might think.

This isn’t just about specs on a spreadsheet. It's about daily usability, camera quality, longevity, and value. Let’s break down what separates these two devices and whether spending extra for the A51 actually pays off.

Design and Build: Subtle but Meaningful Differences

At first glance, both phones share Samsung’s minimalist aesthetic: plastic backs, slim bezels, and centered punch-hole front cameras. However, the A51 feels more refined. It has a slightly slimmer profile (7.9 mm vs 8.6 mm) and a more premium matte finish that resists fingerprints better than the glossy A31.

The A51 also uses a Super AMOLED display—a significant advantage over the A31’s PLS LCD. AMOLED screens deliver deeper blacks, higher contrast, and better outdoor visibility. For media consumption or nighttime scrolling, this difference is immediately noticeable.

Tip: If screen quality matters for streaming or reading, prioritize AMOLED—even if everything else seems equal.

Display Comparison

Feature	Samsung A51	Samsung A31
Screen Type	Super AMOLED	PLS LCD
Size	6.5 inches	6.4 inches
Resolution	1080 x 2400 (FHD+)	720 x 1600 (HD+)
Pixel Density	~405 ppi	~274 ppi

The resolution gap is stark. The A51 delivers Full HD+, while the A31 sticks with HD+. That means sharper text, crisper images, and a noticeably clearer experience when watching videos or browsing social media.

Performance and Hardware: More Than Just RAM

Under the hood, the A51 uses Samsung’s Exynos 9611 processor, while the A31 relies on the older, less powerful MediaTek Helio P65. Both are built on 11nm processes, but the Exynos chip includes a more advanced GPU (Mali-G72 MP3 vs Mali-G52), making it better suited for gaming and multitasking.

In real-world use, the A51 handles app switching more smoothly and maintains consistent frame rates in casual games like Candy Crush or Asphalt 9. The A31 can stutter during transitions or when background apps accumulate.

Both models typically come with 4GB or 6GB of RAM and support microSD expansion up to 512GB. However, the A51 supports faster UFS 2.1 storage, improving app launch speeds and file transfers compared to the eMMC 5.1 used in the A31.

“Even at this price point, storage type and display technology significantly affect long-term satisfaction.” — David Lin, Mobile Hardware Analyst at TechPulse Asia

Camera Capabilities: Where the A51 Pulls Ahead

The rear camera setup may look identical—both have quad cameras—but the implementation differs. The A51 features a 48MP main sensor (f/2.0), while the A31 uses a 48MP sensor too, but with lower light sensitivity and slower processing.

In daylight, photos from both phones are decent, but the A51 produces more balanced exposures, better dynamic range, and finer detail. Low-light performance is where the gap widens. The A51’s software optimization with Night Mode consistently outperforms the A31, capturing brighter scenes with less noise.

The ultrawide, macro, and depth sensors are functionally similar, though the A51 integrates them more seamlessly into its camera interface. Video recording maxes out at 1080p@30fps on both, but the A51 offers slightly better stabilization.

Front Camera Showdown

• A51: 32MP selfie camera with improved skin tone rendering and portrait lighting effects
• A31: 20MP front shooter, adequate for calls and social media, but lacks detail in low light

If you take selfies regularly or use video calling apps, the A51 offers a visibly better experience.

Battery Life and Charging: A Surprise Tie

Despite having a smaller battery (4000mAh vs A31’s 5000mAh), the A51 often lasts just as long due to its more efficient AMOLED display and optimized software. In moderate use—browsing, messaging, some video—the A51 easily lasts a full day. Heavy users may need a top-up by evening.

The A31’s larger battery gives it an edge in endurance testing, especially for users who stream music or watch videos for hours. However, the A51 compensates with faster charging: 15W versus the A31’s 10W. This means the A51 reaches 50% charge in about 30 minutes, while the A31 takes closer to 45.

Tip: Don’t assume bigger battery = longer usability. Screen efficiency and processor optimization play huge roles.

Software and Longevity: Same OS, Different Support Timeline

Both phones launched with Android 10 and Samsung’s One UI 2.0. They received updates to Android 12 and One UI 4.1, but here’s the catch: the A51 was prioritized for patches and feature drops due to its positioning as a “premium mid-ranger.”

Security updates were more frequent on the A51, and community developers later released custom ROMs for it—something rarely seen for the A31. If you plan to keep your phone beyond two years, the A51 offers better long-term viability.

Real-World Example: Maria’s Upgrade Dilemma

Maria bought the A31 in early 2020 for its large battery and affordable price. By late 2021, she noticed her phone slowing down—apps took longer to open, the screen looked dull next to friends’ devices, and her Instagram photos didn’t stand out.

She considered sticking with the A31 but found a refurbished A51 online for only $30 more. After switching, she immediately noticed the brighter, crisper screen and smoother camera experience. “It felt like I upgraded to a completely different class,” she said. “The extra cost was worth every penny.”

Her usage didn’t change—same apps, same habits—but the experience improved significantly. That’s the power of thoughtful hardware choices.

Is It Worth Upgrading? A Practical Checklist

Ask yourself these questions before deciding:

1. Do you value photo quality, especially in low light?
2. Do you watch videos or read on your phone frequently?
3. Are you frustrated by slow app launches or lag?
4. Do you want a phone that feels modern and responsive?
5. Is your current A31 showing signs of slowdown or wear?

If you answered “yes” to three or more, upgrading to the A51 makes sense—even today, years after release.

Frequently Asked Questions

Can the A31 and A51 use the same case?

No. While dimensions are similar, the camera cutout placement and button layout differ slightly. Cases aren’t interchangeable without risking poor fit or blocked sensors.

Does the A51 have a headphone jack?

Yes, both phones include a 3.5mm headphone jack and support USB-C audio adapters.

Which phone has better speakers?

Both have single bottom-firing speakers with no stereo enhancement. Audio quality is tinny at high volumes. Neither excels, but the A51 has marginally clearer output due to better internal tuning.

Final Verdict: Not the Same Phone at All

The Samsung A51 and A31 are not “basically the same.” While they target a similar audience and share design language, the A51 represents a meaningful step up in display quality, performance, camera capability, and long-term usability.

The A31 remains a capable device for basic tasks—calling, texting, light browsing—and its massive battery is still a selling point. But if you care about screen clarity, photo quality, or overall smoothness, the A51 delivers a noticeably better experience.

For anyone considering an upgrade—or choosing between used models today—the extra investment in the A51 is justified. You’re not just paying for specs; you’re paying for a more enjoyable, durable daily driver.

💬 Have you made the switch from A31 to A51? Share your experience below—your insights could help others make a smarter choice!