Design and Display
The Karbonn A21 features a conventional design for its era, accommodating dual Mini-SIM slots which offered flexibility for users managing multiple numbers. While specific dimensions and weight figures are not listed, the phone was typical of its era with a noticeable heft likely due to its plastic build. The device sports a 4.5-inch TFT display, which at the time was fairly large, and it offers a resolution of 480 x 800 pixels. The pixel density of around 207 ppi meant that while it was serviceable for everyday tasks, those with sharper eyes would notice pixelation in fine details.