Galaxy S21 FE 5G • Locked AT&T vs Galaxy S25 Ultra • Unlocked

The Samsung Galaxy S21 FE 5G, released in January 2022, and the Samsung Galaxy S25 Ultra, launched in February 2025, represent different tiers and generations within Samsung's smartphone lineup. While both operate on the Android platform, the S25 Ultra introduces significant advancements in processing power, camera technology, and display quality, reflecting its flagship status and newer release. The S21 FE 5G, on the other hand, offers a balanced experience from an earlier generation.

The longevity of a smartphone is influenced by its release timeline, software support, and physical resilience. These two devices offer different profiles in terms of their expected practical lifespan.

• Release Timeline and Age: The Galaxy S21 FE 5G was released in January 2022, making it an older device compared to the Galaxy S25 Ultra, which launched in February 2025. This age difference directly impacts their remaining software support.
• OS Support Duration: The Galaxy S21 FE 5G launched with Android 12 and received its final major OS upgrade to Android 16 (One UI 8) in October 2025. It is expected to continue receiving security updates for approximately one year beyond its OS upgrade guarantee, which ended in January 2026. In contrast, the Galaxy S25 Ultra launched with Android 15 and is guaranteed seven years of OS and security updates, with support extending until 2032. This provides a significantly longer period of up-to-date software and security.
• Repairability and Durability: Both devices feature an IP68 rating for dust and water resistance. The S21 FE 5G uses Corning Gorilla Glass Victus for screen protection and received a repairability score of 7.5 out of 10, indicating a relatively straightforward repair process for its class. The S25 Ultra, built with a titanium frame and Corning Gorilla Armor 2 on both the front and back, offers enhanced physical durability. It achieved an iFixit repairability score of 5 out of 10, which is considered an improvement for Samsung flagships due to easier battery replacement and modular camera components, though screen repairs remain challenging.

Performance is a key differentiator, with the newer device offering substantial upgrades in processing power and overall system responsiveness.

• Processing Capabilities: The Galaxy S21 FE 5G is powered by a processor that handles everyday applications and multitasking smoothly. The Galaxy S25 Ultra features a current-generation processor designed for demanding tasks, offering significantly improved CPU, GPU, and AI performance. This translates to faster app loading, smoother transitions, and more efficient handling of complex computations.
• Multitasking and Storage: The S21 FE 5G typically comes with 6GB or 8GB of RAM and storage options up to 256GB. The S25 Ultra offers 12GB of RAM in most regions, with a 16GB option in some, and storage capacities ranging from 256GB to 1TB. The increased RAM in the S25 Ultra supports more intensive multitasking and keeps more applications active in the background without slowdowns.
• Real-world Responsiveness: Users of the S21 FE 5G generally report snappy performance for daily use. The S25 Ultra delivers an exceptionally fluid and responsive experience, with animations and transitions appearing instantaneous, making it well-suited for power users and mobile gaming.

The display experience varies between these two models, with the S25 Ultra offering a larger, more advanced panel.

• Display Technology and Clarity: Both devices feature Dynamic AMOLED 2X displays, known for vibrant colors and deep blacks. The S21 FE 5G has a 6.4-inch screen with a Full HD+ resolution (2340 x 1080 pixels), providing clear visuals for general use. The S25 Ultra boasts a larger 6.9-inch screen with a Quad HD+ resolution (3120 x 1440 pixels), resulting in a sharper and more detailed viewing experience.
• Brightness and Outdoor Visibility: The S21 FE 5G offers satisfying levels of brightness for various lighting conditions. The S25 Ultra significantly enhances outdoor usability with a peak brightness of 2600 nits and an anti-glare finish, making its screen easily readable even in bright sunlight.
• Refresh Rate and Smoothness: Both phones feature a 120Hz refresh rate, contributing to smooth scrolling and fluid animations. The S25 Ultra's display is an adaptive LTPO panel, which can dynamically adjust its refresh rate to conserve battery life while maintaining smoothness when needed.

Camera capabilities show a notable progression, with the S25 Ultra featuring a more comprehensive and advanced system.

• Rear Camera Systems: The Galaxy S21 FE 5G includes a triple-camera setup with a 12MP main sensor, an 8MP telephoto lens with 3x optical zoom, and a 12MP ultrawide lens. It performs well in good lighting, producing vibrant and detailed photos. The Galaxy S25 Ultra features a quad-camera system, including a high-resolution 200MP main sensor, a 50MP ultrawide camera, a 10MP telephoto with 3x optical zoom, and a 50MP periscope telephoto with 5x optical zoom. This setup allows for greater versatility and detail capture across various focal lengths.
• Low-Light and Zoom Performance: While the S21 FE 5G's telephoto lens can be less reliable in low-light conditions, its main camera still delivers good results. The S25 Ultra excels in low-light photography, producing stunning images with bright colors and excellent detail. Its multiple telephoto lenses offer impressive zoom capabilities, providing clear results even at higher magnifications.
• Video Recording and Front Camera: Both devices support 4K video recording, with the S21 FE 5G capable of 4K at 60fps. The S25 Ultra elevates video capabilities, supporting up to 8K at 30fps and 4K at 120fps, offering more options for high-quality video content. For selfies, the S21 FE 5G has a 32MP front camera, while the S25 Ultra features a 12MP front camera, both capable of producing clear images.