Both TVs offer adequate brightness levels suitable for most indoor lighting conditions. Intex LED-3900 and Sansui SJX40HB21CAF are two competitive smart TVs offering a mix of display performance, smart features, and overall value for different types of users. Intex LED-3900 features a 39 Inch (99 cm) screen while Sansui SJX40HB21CAF comes with 40 Inch (102 cm), which can make a noticeable difference depending on your room size and viewing distance. Both TVs provide standard built-in audio performance suitable for regular usage, though external speakers can enhance the experience. Both TVs provide decent motion handling, making them suitable for everyday viewing including sports and action content. Overall, both models are capable choices in their segment, offering a balance between performance, features, and usability. Intex LED-3900 and Sansui SJX40HB21CAF differ in resolution (1920 x 1080 vs 1366 x 768), which can affect overall clarity and sharpness of the display. Both TVs come with smart platforms that support popular streaming apps and voice control features.

Verdict: Choosing between Intex LED-3900 and Sansui SJX40HB21CAF depends on your usage, whether you prioritize display quality, smoother motion, or smart features.