Galaxy S21+ 5G vs Galaxy S24 Ultra

When considering the practical lifespan of these devices, their release timelines and software support policies are key differentiators.

• Release and Updates: The Galaxy S21 Plus 5G launched with Android 11 in January 2021 and received four major OS updates, concluding with Android 15 (One UI 7) in May 2025. Security updates for the S21 Plus series ceased in February 2026. In contrast, the Galaxy S24 Ultra, released with Android 14 in January 2024, is promised seven years of OS updates, extending its support through Android 21, along with seven years of security updates.
• Software Longevity: Users prioritizing the longest possible software support and access to the latest Android features will find the S24 Ultra offers a significantly extended lifespan compared to the S21 Plus 5G, which has already reached the end of its major software update cycle.
• Repairability: Both models feature robust builds with glass and aluminum/titanium frames, offering a similar level of repairability for common components. However, the newer S24 Ultra benefits from more recent design and material advancements, such as Gorilla Glass Armor, which may offer enhanced scratch resistance.

The performance capabilities of these two devices reflect the advancements in mobile processing technology over their respective release cycles.

• Processing Power: The Galaxy S21 Plus 5G, equipped with its generation's leading processor, handles everyday applications and multitasking smoothly. For more demanding tasks like intensive gaming or heavy video editing, users might experience occasional warmth and slight performance throttling over extended periods. The Galaxy S24 Ultra, featuring a more recent and powerful processor, delivers a noticeably faster and more responsive experience across all tasks, from launching applications to running graphics-intensive games, with improved thermal management for sustained performance.
• Storage and RAM: The S21 Plus 5G typically comes with 8GB of RAM and storage options of 128GB or 256GB. The S24 Ultra offers 12GB of RAM as standard, with storage options starting at 256GB and going up to 1TB, providing more headroom for multitasking and significantly more space for applications, media, and files.
• Battery Behavior: The S21 Plus 5G houses a 4800 mAh battery, which generally provides a full day of moderate use, though heavy users might find themselves needing to recharge before the day ends. The S24 Ultra features a 5000 mAh battery, and coupled with its more efficient processor and adaptive display technology, users frequently report excellent battery life, often lasting through a full day of heavy use with screen-on times of 7-8 hours.

Both devices feature high-quality AMOLED displays, but the S24 Ultra incorporates several enhancements that contribute to a superior visual experience.

• Display Technology and Resolution: The Galaxy S21 Plus 5G features a 6.7-inch Dynamic AMOLED 2X display with a resolution of 1080 x 2400 pixels, offering vibrant colors and deep blacks. The Galaxy S24 Ultra boasts a slightly larger 6.8-inch Dynamic LTPO AMOLED 2X display with a higher resolution of 1440 x 3120 pixels, resulting in sharper text and more detailed images.
• Brightness and Refresh Rate: The S21 Plus 5G offers an adaptive refresh rate up to 120Hz and a peak brightness of 1300 nits, providing smooth scrolling and good visibility in most lighting conditions. The S24 Ultra significantly elevates this with a 1-120Hz adaptive refresh rate and an impressive peak brightness of 2600 nits, ensuring exceptional outdoor visibility even in direct sunlight, and a smoother, more power-efficient display experience.
• Viewing Experience: The S24 Ultra also benefits from a new anti-glare coating and Gorilla Glass Armor, which further enhances outdoor viewing and provides increased durability against scratches. The S21 Plus 5G uses Gorilla Glass Victus for protection.

The camera systems on both devices are capable, but the S24 Ultra introduces substantial upgrades, particularly in resolution and zoom capabilities.

• Rear Camera System: The Galaxy S21 Plus 5G features a triple camera setup with a 12 MP main sensor, a 64 MP telephoto lens with 3x hybrid optical zoom, and a 12 MP ultrawide lens. The Galaxy S24 Ultra significantly upgrades this with a quad-camera system, including a 200 MP main sensor, a 10 MP telephoto with 3x optical zoom, a 50 MP periscope telephoto with 5x optical zoom, and a 12 MP ultrawide lens.
• Photography Performance: While the S21 Plus 5G delivers good everyday photos, the S24 Ultra excels with greater detail, improved low-light performance, and more versatile zoom options, allowing for clearer distant shots. Users often praise the S24 Ultra's camera for its clarity, color reproduction, and dynamic range.
• Video Recording and Audio: Both phones support 8K video recording, with the S24 Ultra offering more frame rate options for 4K and 8K. The S24 Ultra also benefits from advancements in microphone quality for clearer audio recording and calls, and both offer stereo speakers for media consumption.

Beyond the core specifications, several other features contribute to the overall user experience and differentiate these two Samsung flagships.

• Connectivity: Both devices support 5G connectivity. The S21 Plus 5G features Wi-Fi 6 and Bluetooth 5.0. The S24 Ultra offers newer standards with Wi-Fi 7 and Bluetooth 5.3, providing potentially faster and more stable wireless connections.
• Ports and Sensors: Both utilize a USB-C port for charging and data transfer. Both include an under-display fingerprint sensor, accelerometer, gyro, proximity, compass, and barometer. The S24 Ultra's ultrasonic fingerprint sensor is generally considered more reliable.
• Design and Build Materials: The S21 Plus 5G features a glass front and back (Gorilla Glass Victus) with an aluminum frame. The S24 Ultra upgrades to a titanium frame and Gorilla Glass Armor on the front, offering enhanced durability and a more premium feel. The S24 Ultra also integrates the S Pen stylus, offering additional functionality for note-taking and navigation.
• Dimensions and Handling: The S21 Plus 5G measures 161.5 x 75.6 x 7.8 mm and weighs 200g. The S24 Ultra is slightly larger and heavier at 162.3 x 79 x 8.6 mm and 232g, which, combined with its flat display, can impact one-handed use.