Galaxy S21 Ultra 5G • Unlocked vs OnePlus 12 • Unlocked

The Samsung Galaxy S21 Ultra 5G, released in January 2021, and the OnePlus 12, launched globally in early 2024, represent different generations of flagship Android smartphones. While both devices aim to deliver a premium mobile experience, the OnePlus 12 benefits from newer hardware and software advancements, particularly in processing power and charging technology. Both operate on the Android platform, offering distinct user interfaces with Samsung's One UI and OnePlus's OxygenOS.

The expected lifespan of a smartphone is influenced by its release date, software support, and physical durability.

• Release Timeline: The Galaxy S21 Ultra 5G was released in January 2021, making it an older device compared to the OnePlus 12, which launched globally in early 2024. This age difference directly impacts their remaining software support.
• OS Support Duration: The Galaxy S21 Ultra 5G received four major Android OS updates, concluding with Android 15 (One UI 7.0) in the first half of 2025, and security patches were expected to continue quarterly until early 2026. The OnePlus 12 is promised four years of Android updates and five years of security patches, meaning it is expected to receive updates until at least Android 18.
• Repairability: The Galaxy S21 Ultra 5G received a repairability score of 3 out of 10 from iFixit, largely due to the extensive use of glue and a non-modular display cable, making repairs challenging. The OnePlus 12 has a moderate repairability score, with some components being accessible despite the use of adhesive.
• Physical Durability: Both devices feature robust builds. The Galaxy S21 Ultra 5G has an IP68 rating for dust and water resistance and uses Gorilla Glass Victus on both the front and back. The OnePlus 12 carries an IP65 rating for dust and water resistance and features Corning Gorilla Glass Victus 2 for screen protection.

Performance differences between these two devices are notable, primarily due to the generational gap in their internal components.

• Processor Capabilities: The Galaxy S21 Ultra 5G is powered by a processor from 2021, which capably handles everyday tasks and demanding applications. The OnePlus 12, featuring a newer generation processor, offers faster CPU and GPU speeds, resulting in smoother performance for intensive gaming and complex multitasking.
• System Responsiveness: Users transitioning from the S21 Ultra 5G to the OnePlus 12 often report a noticeable increase in snappiness and overall system responsiveness, with faster app launches and reduced lag. The OnePlus 12 also incorporates a large vapor chamber cooling system to maintain performance during extended heavy use.
• RAM and Storage: Both devices offer ample RAM, with the Galaxy S21 Ultra 5G available with up to 16GB and the OnePlus 12 with up to 16GB (with some regional variants offering 24GB). Storage options are generous on both, ranging from 128GB to 512GB for the S21 Ultra 5G and 256GB to 512GB for the OnePlus 12, utilizing modern storage standards for quick data access.
• Battery Behavior: The Galaxy S21 Ultra 5G features a 5000 mAh battery, providing a full day of use for many users. The OnePlus 12 comes with a larger 5400 mAh battery, which, combined with a more power-efficient processor, generally offers excellent battery life. The OnePlus 12 also supports significantly faster wired charging at 100W (80W in the US) and 50W wireless charging, compared to the S21 Ultra 5G's 25W wired and 15W wireless charging.

Both smartphones offer high-quality displays, but there are distinctions in their technology and peak brightness.

• Display Technology and Resolution: The Galaxy S21 Ultra 5G features a 6.8-inch Dynamic AMOLED 2X display with a resolution of 3200 x 1440 pixels. The OnePlus 12 sports a slightly larger 6.82-inch LTPO AMOLED display with a resolution of 3168 x 1440 pixels. Both offer sharp visuals and vibrant colors.
• Refresh Rate and Smoothness: Both devices provide an adaptive refresh rate of up to 120Hz, ensuring smooth scrolling and responsive interactions. The LTPO technology in the OnePlus 12 allows for a more dynamic adjustment of the refresh rate, potentially contributing to better power efficiency.
• Brightness Levels: The Galaxy S21 Ultra 5G can reach a peak brightness of 1500 nits, offering good visibility in bright conditions. The OnePlus 12 significantly surpasses this with a peak brightness of 4500 nits, making it exceptionally bright and easy to view even in direct sunlight.
• Viewing Experience: Both displays support HDR10+, with the OnePlus 12 also featuring Dolby Vision, enhancing the contrast and color accuracy for compatible content. The curved edges on both phones contribute to an immersive viewing experience.

The camera systems on both the Galaxy S21 Ultra 5G and the OnePlus 12 are designed for versatility, though they approach imaging with different sensor configurations and processing.

• Rear Camera Systems: The Galaxy S21 Ultra 5G features a quad-camera setup with a 108MP main sensor, a 12MP ultrawide, a 10MP telephoto with 3x optical zoom, and a 10MP periscope telephoto with 10x optical zoom. The OnePlus 12 offers a triple camera system, including a 50MP main sensor, a 64MP periscope telephoto with 3x optical zoom (and 6x in-sensor zoom), and a 48MP ultrawide lens, benefiting from Hasselblad Color Calibration.
• Photography Performance: The S21 Ultra 5G is known for its detailed images and impressive zoom capabilities, particularly with its dual telephoto lenses. The OnePlus 12, with its newer main sensor and Hasselblad tuning, delivers vivid colors and sharp images, with users noting its strong performance in various lighting conditions.
• Low-Light and Video: Both devices are capable of capturing good low-light photos, though the newer sensors and processing in the OnePlus 12 may offer an advantage in challenging conditions. For video, both support 8K recording at 24fps and 4K at 30/60fps, with the OnePlus 12 also featuring Dolby Vision for video.
• Front Camera: The Galaxy S21 Ultra 5G has a 40MP front camera, while the OnePlus 12 features a 32MP front camera. Both are capable of capturing detailed selfies and supporting high-quality video calls.
• Audio Experience: Both smartphones are equipped with stereo speakers, providing a rich audio experience for media consumption.