Design# OnePlus 9: 160 x 74.2 x 8.7mm, 192g OnePlus 9 Pro: 163.2 x 73.6 x 8.7mm, 197g S21: 151.7 x 71.2 x 7.9mm, 172g S21+: 161.5 x 75.6 x 7.8mm, 202g S21 Ultra: 165.1 x 75.6 x 8.9mm, 228g Display# OnePlus 9: 6.55-inches, 2400 x 1080, 120Hz OnePlus 9 Pro: 6.7-inches, 3216 x 1440, 1Hz-120Hz S21: 6.2-inches, 2400 x 1080 pixels, 48-120Hz S21+: 6.7-inches, 2400 x 1080 pixels, 48-120Hz S21 Ultra: 6.8-inches, 3200 x 1440 pixels, 10-120Hz, S Pen Hardware and specs# OnePlus 9: Qualcomm Snapdragon 888, 8GB, 128GB/256GB, 4500mAh OnePlus 9 Pro: Qualcomm Snapdragon 888, 8GB/12GB, 128GB/256GB, 4500mAh S21: Qualcomm Snapdragon 888 or Exynos 2100, 8GB, 128/256GB, 4000mAh S21+: Qualcomm Snapdragon 888 or Exynos 2100, 8GB, 128/256GB, 4800mAh S21 Ultra: Qualcomm Snapdragon 888 or Exynos 2100, 12/16GB, 128/256/512GB, 5000mAh Camera# OnePlus 9: Triple (48MP + 50MP + 2MP), 16MP front camera OnePlus 9 Pro: Quad rear (48MP + 50MP + 2MP + 8MP), 16MP front camera S21: Triple rear (12MP + 12MP + 64MP), 10MP front camera S21+: Triple rear (12MP + 12MP + 64MP), 10MP front camera S21 Ultra: Quad rear (108MP + 12MP + 10MP + 10MP), 40-megapixel front camera Price# OnePlus 9 series: From £629 Samsung Galaxy S21 series: From £769 Conclusion# 