Galaxy S8 Vs S21 Is It Really Worth The Upgrade In 2025

The Samsung Galaxy S8 was a landmark device when it launched in 2017. Its edge-to-edge display, premium design, and solid performance made it one of the most desirable Android phones of its era. Fast forward to 2025, and the Galaxy S21—released in early 2021—still holds up as a capable flagship. But for users still holding onto an S8, the question arises: after nearly eight years, is moving from the S8 to the S21 actually worthwhile?

This isn’t just about newer hardware or better specs. It’s about real-world usability, longevity, security, and whether the investment makes sense in today’s mobile landscape. Let’s examine the key differences and practical implications of this upgrade path.

Performance: From Flagship Past to Modern Powerhouse

The Galaxy S8 was powered by either the Qualcomm Snapdragon 835 or Exynos 8895, depending on region—both were top-tier chips in 2017. At the time, they delivered smooth multitasking, excellent app responsiveness, and strong gaming performance. However, by 2025 standards, these processors struggle with modern apps, especially those leveraging AI features, high-resolution media, or background-heavy services.

In contrast, the Galaxy S21 runs on either the Snapdragon 888 or Exynos 2100 (again, region-dependent). These chips are built on more advanced architectures, support 5G connectivity, and offer significantly better CPU and GPU performance. Real-world usage shows that the S21 handles app launches, photo editing, video rendering, and even light gaming far more efficiently than the S8.

Tip: If your current phone lags when opening messaging apps or takes more than two seconds to launch the camera, it’s likely time for a hardware upgrade.

For example, launching Google Photos on the S8 can take 4–5 seconds due to storage slowdowns and RAM limitations. On the S21, it opens instantly. This kind of day-to-day responsiveness adds up over time and directly impacts user satisfaction.

Display and Design: Evolution of Form and Function

The S8 introduced Samsung’s Infinity Display—a curved, edge-to-edge 5.8-inch Quad HD+ AMOLED panel that felt futuristic at the time. In 2025, that screen still looks decent, but it lacks brightness, refresh rate, and durability improvements seen in later models.

The S21 improves on this with a 6.2-inch Dynamic AMOLED 2X display with a 120Hz adaptive refresh rate. This means smoother scrolling, more responsive touch input, and better outdoor visibility thanks to higher peak brightness (up to 1300 nits vs. ~1000 on the S8).

Design-wise, both phones feature glass backs and aluminum frames, but the S21 is slightly heavier and more compact in bezel size. While the S8 has IP68 water resistance, the S21 maintains that while improving speaker quality and microphone placement for clearer calls and audio recording.

“Display fluidity and brightness are now baseline expectations. A 60Hz screen feels outdated in daily use, especially when switching between apps.” — David Kim, Mobile UX Analyst at TechInsight Group

Camera Capabilities: Night and Day Difference

Camera technology has evolved dramatically since 2017. The S8 featured a single 12MP rear sensor with Dual Pixel autofocus and f/1.7 aperture—an excellent shooter for its time. But it lacked optical image stabilization (OIS) in some regions, had limited low-light performance, and no ultra-wide lens.

The S21 brings a triple-camera setup: 12MP wide, 12MP ultra-wide, and a 64MP telephoto with 3x hybrid zoom. More importantly, it benefits from years of computational photography advances. Features like Night Mode, AI scene optimization, improved HDR, and better noise reduction make a tangible difference in photo quality—especially in dim lighting.

Video recording jumps from 4K at 30fps on the S8 to 8K at 24fps on the S21, though most users will find the improved 4K stabilization and audio capture more valuable in practice.

Feature	Galaxy S8	Galaxy S21
Rear Cameras	12MP (f/1.7)	12MP (wide) + 12MP (ultra-wide) + 64MP (telephoto)
Front Camera	8MP (f/1.7)	10MP (f/2.2)
Video Recording	4K @ 30fps	8K @ 24fps, 4K @ 60fps
Night Mode	No	Yes (with AI enhancement)
Zoom Capability	Digital only	3x Hybrid Zoom, up to 30x Super Resolution Zoom

Battery Life and Charging: Practical Endurance Matters

The S8 came with a 3000mAh battery—modest even for its time. By 2025, after years of charge cycles, most S8 batteries have degraded significantly, often lasting less than a full day with moderate use. Fast charging is limited to 15W, and wireless charging is supported but slow.

The S21 packs a 4000mAh battery, which combined with more efficient software and processor architecture, typically lasts a full day and a half under average conditions. It supports 25W fast charging (though no charger included), 15W wireless charging, and reverse wireless charging—letting you power up earbuds or another phone in a pinch.

If you're currently charging your S8 twice a day or carrying a power bank, the S21 offers meaningful relief in terms of convenience and freedom.

Tip: Check your battery health in settings. If maximum capacity is below 75%, consider replacement or upgrade—even if the phone seems functional.

Software Support and Security: The Hidden Upgrade Factor

One of the most overlooked aspects of upgrading is long-term software support. The Galaxy S8 originally launched with Android 7 and received updates up to Android 10. As of 2025, it hasn’t received a security patch in over three years, making it vulnerable to emerging threats.

The Galaxy S21, meanwhile, launched with Android 11 and is eligible for four major OS upgrades and five years of security patches—meaning it should receive updates until at least 2026. This ensures compatibility with modern banking apps, messaging platforms, and productivity tools that increasingly require recent Android versions.

Samsung’s One UI has also matured significantly, offering better customization, privacy controls, and integration with other devices like Galaxy Buds or SmartThings appliances.

Mini Case Study: Maria’s Upgrade Dilemma

Maria, a freelance photographer based in Austin, held onto her Galaxy S8 primarily because it still took acceptable photos and she didn’t want to spend money unnecessarily. However, by late 2024, she noticed her banking app stopped working, her cloud backups failed intermittently, and her phone overheated during simple tasks.

After testing a friend’s used S21, she was struck by how quickly apps loaded, how clear the night photos were, and how the phone stayed cool during extended use. She upgraded in January 2025 and reported immediate improvements in workflow efficiency. “It’s not just faster—it feels secure and reliable again,” she said.

Is the Upgrade Worth It in 2025? A Practical Checklist

Before deciding, evaluate your current needs using this checklist:

• ✅ Does your S8 frequently freeze, crash, or fail to install app updates?
• ✅ Have you replaced the battery recently, yet still get less than 6 hours of screen time?
• ✅ Do you need better camera quality for work, social media, or family moments?
• ✅ Are you concerned about data security or unable to use essential apps?
• ✅ Do you value longer software support and access to new features?

If three or more apply, the S21 represents a justified upgrade—even in 2025. And given the availability of refurbished or second-hand S21 units at $150–$200, the cost barrier is lower than ever.

Frequently Asked Questions

Can the Galaxy S8 still be used safely in 2025?

Possibly, but not recommended for sensitive tasks like online banking or email. Without security updates, it's vulnerable to malware and phishing attacks. Use only for basic functions or as a secondary device.

Is the Galaxy S21 future-proof for the next few years?

While not cutting-edge, the S21 remains functional for everyday use through 2026. Performance may slow with future Android versions, but it will likely remain secure and compatible with mainstream apps.

Should I skip to a newer model like the S23 or S24 instead?

If budget allows, yes. Newer models offer better efficiency, improved cameras, and longer support. But for S8 users seeking a significant leap without overspending, the S21 delivers 80% of the benefit at half the price.

Final Verdict: Yes, It’s Worth It—With Caveats

Upgrading from the Galaxy S8 to the S21 in 2025 isn't about chasing the latest trend. It's about reclaiming reliability, security, and usability. The performance gap is substantial, the camera is vastly superior, and the software experience is aligned with modern expectations.

That said, ensure you’re buying a well-maintained S21 with healthy battery life. Consider refurbished units from reputable sellers, and pair the upgrade with a protective case and screen protector to extend its lifespan.

💬 Have you made the jump from S8 to S21—or skipped ahead? Share your experience and tips in the comments to help others decide!