Samsung S21 Vs S24 Is The Upgrade Necessary If My Phone Still Works

For millions of smartphone users, the question isn't whether the latest flagship is impressive—it's whether the upgrade is truly necessary. If you're still using a Samsung Galaxy S21 and it’s functioning well, the arrival of the Galaxy S24 might not feel like an urgent call to action. After all, replacing a working device every year or two isn’t just expensive; it contributes to e-waste and often delivers diminishing returns. So, is stepping up from the S21 to the S24 actually worthwhile? The answer depends on what you value in a phone, how you use it, and what kind of experience you’re willing to pay for.

This comparison goes beyond raw specs. It considers real-world usability, longevity, software support, camera evolution, and overall user satisfaction. By the end, you’ll have a clear picture of whether the S24 brings meaningful improvements—or if holding onto your S21 is the smarter, more sustainable choice.

Performance: Speed, Longevity, and Future-Proofing

The heart of any smartphone is its processor, and here the gap between the S21 and S24 is significant. The Galaxy S21 launched with the Qualcomm Snapdragon 888 (or Exynos 2100 in some regions), a powerful chip at the time but known for thermal throttling under sustained loads. In contrast, the Galaxy S24 runs on the Snapdragon 8 Gen 3, built on a more efficient 4nm process, offering substantially better performance and power management.

In practical terms, this means faster app launches, smoother multitasking, quicker photo and video processing, and better gaming performance. The S24 handles modern games at high settings without breaking a sweat, while the S21 may struggle with newer titles or extended gameplay due to heat buildup.

Beyond raw speed, future-proofing matters. Samsung has committed to seven years of OS and security updates for the S24 series—until 2031. The S21, by comparison, will receive updates until 2025. That four-year difference could be crucial if you plan to keep your phone long-term.

Tip: If you rely on your phone for productivity or plan to keep it beyond three years, longer software support makes a major difference in security and app compatibility.

Camera Improvements: Subtle Gains Over Generational Leaps

The camera is often the deciding factor in an upgrade, but the evolution from the S21 to the S24 is more about refinement than revolution. Both phones feature a triple-lens rear setup: a 12MP ultra-wide, a 12MP main sensor, and a 64MP telephoto with 3x hybrid zoom. On paper, they look similar—but real-world results tell a different story.

The S24’s camera system benefits from improved image processing, larger pixel sizes, better low-light algorithms, and AI-enhanced photography features. Night mode shots are brighter with less noise, dynamic range is wider, and autofocus is faster. The front-facing camera also sees a bump from 10MP to 12MP, with better skin tone rendering and background blur in portrait mode.

One standout addition is the \"Zoom Lock\" feature, which stabilizes images at high magnification, making 10x or even 30x digital zoom more usable. While the S21 can zoom, the results are often soft or blurry beyond 5x.

However, if you're not a frequent photographer or don’t print large images, these differences may not justify the cost of a new phone. For casual social media sharing, the S21’s camera remains perfectly capable.

“Camera hardware evolves slowly, but computational photography is where the real gains happen. The S24 leverages AI to close the gap between professional and mobile photography.” — David Lin, Mobile Imaging Analyst at TechVision Labs

Battery Life and Charging: Efficiency Matters More Than Capacity

Battery capacity hasn’t increased dramatically—the S21 has a 4000mAh battery, the S24 a 4000mAh unit as well—but efficiency has improved. Thanks to the more power-efficient chipset and optimized software, the S24 typically lasts 15–20% longer on a single charge under mixed usage.

In real-world testing, that translates to about 6–7 hours of screen-on time for the S21 versus 7.5–8.5 hours for the S24. This may not sound like much, but over a day of heavy use, it can mean the difference between needing a midday charge and making it through comfortably.

Charging speeds remain unchanged: both support 25W wired fast charging and 15W wireless charging. Neither includes a charger in the box. However, the S24 charges slightly faster due to better thermal management during high-speed charging cycles.

If your S21’s battery has degraded after three years of use, the S24 offers a tangible improvement. But if your current battery health is still above 85%, the daily difference may not be noticeable enough to warrant an upgrade.

Display and Design: A Familiar Feel With Refined Details

Both the S21 and S24 feature 6.2-inch Dynamic AMOLED 2X displays with a 120Hz refresh rate, HDR10+ support, and excellent brightness. The S24’s screen peaks at 2600 nits, compared to the S21’s 1300 nits, making it significantly more readable in direct sunlight.

The design language has evolved subtly. The S24 adopts flatter edges and a more minimalist camera housing, giving it a modern, premium feel. It’s also slightly heavier (167g vs 169g) but feels more balanced in hand. The build quality uses stronger Gorilla Glass Victus 2 on the front and back, improving scratch and drop resistance.

One notable omission: the S21 supported microSD cards for expandable storage; the S24 does not. If you rely on external storage for photos or videos, this could be a drawback.

Feature	Samsung Galaxy S21	Samsung Galaxy S24
Processor	Snapdragon 888 / Exynos 2100	Snapdragon 8 Gen 3
RAM	8GB	8GB
Storage Options	128GB, 256GB (expandable via microSD)	128GB, 256GB, 512GB (no microSD)
Battery	4000mAh	4000mAh
Charging	25W wired, 15W wireless	25W wired, 15W wireless
Software Support Until	2025	2031
Display Brightness (Peak)	1300 nits	2600 nits
Water Resistance	IP68	IP68

Real-World Decision Making: When the Upgrade Makes Sense

Let’s consider a realistic scenario. Maria has used her Galaxy S21 since early 2021. She’s careful with her devices, uses a case and screen protector, and hasn’t experienced any hardware issues. Her battery drains around 60% after a full workday, which she manages with a portable charger. She takes occasional photos, mostly for Instagram, and uses her phone for emails, streaming, and messaging.

She’s intrigued by the S24’s AI features—like Circle to Search and live translation—but wonders if they’re gimmicks or genuinely useful. After testing the S24 at a store, she notices the screen is easier to see outdoors, apps open faster, and the camera focuses instantly in low light. However, none of these changes solve a pressing problem she currently faces.

Maria decides to wait. She invests $100 in a battery replacement for her S21, extending its life by another 1–2 years. By doing so, she saves over $700 and reduces electronic waste. Her decision reflects a growing trend: consumers are becoming more intentional about upgrades, prioritizing sustainability and value over novelty.

The takeaway? If your S21 meets your daily needs, shows no signs of slowing down, and the battery holds charge reasonably well, upgrading solely for the S24’s incremental gains may not be justified.

Upgrade Checklist: Is the S24 Right for You?

Before making the leap, ask yourself the following:

• Am I experiencing frequent app crashes or lag when multitasking?
• Do I regularly shoot photos or videos in low light and need better quality?
• Is my current battery life insufficient for a full day without charging?
• Do I want access to the latest AI-powered features and seven years of updates?
• Am I concerned about long-term software support and security?
• Can I afford the upgrade without financial strain?

If you answered “yes” to three or more of these, the S24 likely offers meaningful benefits. If not, your S21 is still a capable device.

Step-by-Step: How to Evaluate Your Need for an Upgrade

1. Assess Performance: Open your most-used apps and switch between them. Does the phone stutter or reload frequently?
2. Check Battery Health: Use Samsung’s built-in diagnostics (Settings > Device Care > Battery) to see if capacity is below 80%.
3. Test Camera Output: Take sample photos in daylight, low light, and zoom mode. Compare them to recent S24 samples online.
4. Review Software Experience: Are you missing out on features available only on newer models?
5. Research Trade-In Value: Check what your S21 is worth toward a new device. Sometimes trade-ins reduce the effective cost significantly.
6. Try Before You Buy: Visit a retailer to test the S24 side by side with your S21.
7. Make a Decision: Based on real needs—not marketing—decide whether to upgrade, repair, or wait.

Tip: Reset your S21 to factory settings to eliminate software bloat. You might be surprised how much faster it feels.

Frequently Asked Questions

Will the Galaxy S21 still receive updates in 2024?

Yes. Samsung has confirmed Android 14 and security updates for the S21 through 2025. You’ll continue receiving monthly or quarterly patches, ensuring your device remains secure and compatible with most apps.

Are the AI features on the S24 worth it?

It depends on your usage. Features like Circle to Search, generative edit in Gallery, and live call translation are convenient but not essential. Power users and tech enthusiasts may appreciate them; casual users may rarely use them.

Can I extend the life of my S21 instead of upgrading?

Absolutely. Replace the battery if it’s degraded, use a protective case, keep software updated, and avoid exposing the phone to extreme temperatures. These steps can easily extend your S21’s lifespan to 2026 or beyond.

Final Thoughts: Value Beyond Specs

The Galaxy S24 is undeniably a better phone than the S21—faster, brighter, smarter, and built to last longer in terms of software. But “better” doesn’t always mean “necessary.” If your S21 still powers through your day without issue, upgrading may be more about desire than need.

Smartphone technology has matured. Year-over-year improvements are now subtle rather than transformative. At the same time, environmental awareness and economic pressures are pushing consumers to rethink upgrade cycles. Holding onto a functional device isn’t falling behind—it’s making a conscious, responsible choice.

That said, if you’re a power user, rely on your phone for creative work, or simply love having the latest technology, the S24 delivers a polished, future-ready experience. Just ensure your decision is based on real utility, not FOMO.

💬 What’s your take? Are you upgrading from the S21 to the S24—or sticking with what works? Share your thoughts and experiences in the comments below.