Galaxy A51 vs Galaxy S21 5G

The Samsung Galaxy A51, released in December 2019, and the Samsung Galaxy S21 5G, launched in January 2021, represent different segments of Samsung's smartphone offerings. While both devices operate on the Android platform, the Galaxy S21 5G arrived as a flagship model with advanced features, whereas the Galaxy A51 was positioned as a mid-range option. Key differentiators lie in their processing power, display technology, and camera capabilities, reflecting their respective market positions and release timelines.

The longevity of a smartphone is influenced by its release timeline, software support, and physical resilience. The Galaxy A51, being an older device, has reached the end of its software update cycle, while the Galaxy S21 5G still receives security updates.

• Software Support: The Galaxy A51, initially launched with Android 10, was promised three major OS updates, concluding with Android 13, and four years of security updates. Software support for the 4G model ended around early 2024, and for the 5G model, it concluded in mid-2024. In contrast, the Galaxy S21 5G, released with Android 11, was part of a policy that offered three major OS updates and four years of security updates, meaning it continues to receive security patches.
• Repairability: The Galaxy A51 has an estimated repairability score of around 6 to 6.5 out of 10, indicating that while components like the battery and screen can be replaced, the process involves adhesive and small parts, often requiring specialized tools. The Galaxy S21 5G has a varied repairability assessment, with some sources giving it a 7.5 or 7.75 out of 10, noting its easily removable back plate and modular components. However, other assessments, like iFixit, rated it lower at 4 out of 10, citing difficulties with battery removal due to strong adhesive and the screen's fragility.
• Physical Durability: The Galaxy A51 features a plastic back and frame for the 4G variant, with the 5G variant having a plastic back and aluminum frame, and it lacks an official water resistance rating. The Galaxy S21 5G, while also featuring a plastic back, has a metal frame and boasts an IP68 rating for dust and water resistance, offering better protection against environmental elements.

Performance is a critical aspect for daily smartphone use, encompassing how smoothly applications run, the device's responsiveness, and its ability to handle demanding tasks. These two devices offer different levels of capability in this regard.

• Processing Power: The Galaxy A51 is equipped with a processor that, while capable for general use, has been noted by some reviewers to offer underwhelming performance, occasionally making the Android operating system feel less fluid. The Galaxy S21 5G, on the other hand, features a more advanced processor designed for flagship performance, resulting in noticeably faster speeds and smoother operation across various applications and multitasking scenarios.
• Multitasking and App Responsiveness: For users who frequently switch between multiple applications or engage in more intensive tasks like mobile gaming, the Galaxy S21 5G provides a more responsive and fluid experience due to its higher-tier internal components. The Galaxy A51 may exhibit slight delays or slower loading times when handling numerous applications simultaneously or running graphically intensive games.
• Storage and Memory: The Galaxy A51 offers various configurations, including 4, 6, or 8 GB of RAM and storage options from 64 GB to 256 GB, with microSD expansion capability up to 512 GB or 1 TB. The Galaxy S21 5G typically comes with 8 GB of RAM and internal storage options of 128 GB or 256 GB, but it does not support expandable storage via microSD card.

The visual experience on a smartphone is largely defined by its display, with differences in technology, resolution, and refresh rate impacting clarity and smoothness.

• Display Technology and Clarity: Both devices feature Super AMOLED displays, known for vibrant colors and deep blacks. The Galaxy A51 has a 6.5-inch Super AMOLED display with a Full HD+ resolution (1080x2400 pixels) and a pixel density of approximately 405 PPI, protected by Corning Gorilla Glass 3. The Galaxy S21 5G features a 6.2-inch Dynamic AMOLED 2X display, also with Full HD+ resolution (1080x2400 pixels) and a slightly higher pixel density of around 421 PPI, protected by the more advanced Corning Gorilla Glass Victus.
• Refresh Rate and Brightness: A significant difference lies in the refresh rate. The Galaxy A51 operates at a standard 60Hz refresh rate. The Galaxy S21 5G, however, offers an adaptive refresh rate that can dynamically adjust between 48Hz and 120Hz, providing a smoother scrolling and viewing experience, particularly noticeable in fast-paced content or gaming. In terms of brightness, the Galaxy A51 can reach a peak brightness of around 565 nits, while the Galaxy S21 5G can achieve a significantly higher peak brightness of up to 1300 nits, improving outdoor visibility and HDR content viewing.
• Viewing Experience: The Galaxy S21 5G's Dynamic AMOLED 2X display with its adaptive 120Hz refresh rate and higher peak brightness offers a more fluid and immersive viewing experience, especially in varying lighting conditions. The Galaxy A51 still provides a good visual experience with its Super AMOLED panel, but it lacks the advanced smoothness and brightness capabilities of the S21 5G.

Camera systems are a primary consideration for many users, with capabilities varying significantly between different smartphone models, impacting photo and video quality in diverse conditions.

• Rear Camera System: The Galaxy A51 features a quad-camera setup with a 48MP main sensor that uses pixel-binning to produce 12MP images, a 12MP ultrawide lens, a 5MP macro lens, and a 5MP depth sensor. It generally performs well in daylight, producing images with saturated colors and decent dynamic range. The Galaxy S21 5G sports a triple-camera system, including a 12MP ultrawide, a 12MP wide-angle, and a 64MP telephoto lens. This configuration offers improved focus, subject tracking, and overall image processing.
• Low-Light and Video Performance: The Galaxy A51's low-light photography is a known weakness, often resulting in noise and less vibrant colors. It supports 4K video recording, but the main lens lacks optical image stabilization (OIS), relying on electronic image stabilization (EIS). The Galaxy S21 5G demonstrates better low-light performance with its night mode and improved sensors. It is capable of recording 8K video and 4K video at 60 frames per second across all its rear lenses, offering superior video quality and stabilization.
• Front Camera and Audio: For selfies, the Galaxy A51 has a 32MP front camera. The Galaxy S21 5G features a 10MP selfie camera, which provides good detail and dynamic range. In terms of audio, the Galaxy A51 includes a 3.5mm headphone jack and active noise cancellation with a dedicated mic. The Galaxy S21 5G does not have a 3.5mm headphone jack, but offers an improved speaker assembly for media consumption.