Compare phones
| Global Score | |
| 73.5 | 84.1 |
| Basic Information | |
| Samsung | Samsung |
| Android 9.0 Pie, 7.0 Nougat | Android 11, 10 |
| 2017-07-01 | 2020-03-23 |
| 6.00 x 2.94 x 0.31 inches | 6.26 x 2.96 x 0.35 inches |
| 6.38 ounces | 6.63 ounces |
| Black, Gold, Rose gold and Silver | Midnight blue and Raven black |
| Aluminum | Plastic and Plastic |
| -- | Scratch-Resistant Glass |
| Display / Screen | |
| 5.5 inches | 6.4 inches |
| 1920 x 1080 pixels (Full HD) | 2340 x 1080 pixels |
| Super AMOLED | Super AMOLED |
| 401 pixels per inch | 403 pixels per inch |
| -- | 420 cd/m2 brightness |
| No touch screen | No touch screen |
| 7.9 | 8.4 |
| Performance | |
| Samsung Exynos 7 Octa 7870 chipset | Exynos 9611 chipset |
| ARM Cortex-A53, 64-bit, 14 nm (Octa-Core 1600 MHz) processor | Arm Cortex-A73 and Arm Cortex-A53, 64-bit, 10 nm (Octa-Core 2300 MHz) processor |
| 3 GB RAM | 4 GB RAM |
| Mali-T830 MP2 GPU | Mali-G72 MP3 GPU |
| 8.73 | 9.27 |
| Storage | |
| 16 GB internal memory | 64 GB internal memory |
| microSDXC (up to 256 GB) external memory slot | microSDXC (up to 512 GB) external memory slot |
| 7.48 | 11.74 |
| Camera | |
| 13.00 MP + 13.00 MP | 48.00 MP + 20.00 MP |
| f/1.70 aperture | f/2.00 aperture |
| -- | 26.00mm focal length |
| -- | 0.5 inches (1/2") sensor |
| 1920 x 1080 (30 fps) (Full HD) video resolution | 3840 x 2160 (30 fps) (4K) video resolution |
| -- | 1920 x 1080 (240 fps) (Full HD) slow motion video |
| 9.02 | 11.55 |
| Networks | |
| Wi-Fi | Wi-Fi |
| Mobile Hotspot | Mobile Hotspot |
| LTE-A (4G), LTE (4G), HSPA+ (4G), HSDPA and HSUPA | LTE-A (4G), LTE (4G), HSPA+ (4G), HSDPA and HSUPA |
| Nano SIM, Dual SIM | Nano SIM, Dual SIM |
| 6.7 | 6.7 |
| Battery Life | |
| 3600mAh Battery | 6000mAh Li - Polymer Battery |
| Non-Removable Battery | Non-Removable Battery |
| 5.6 | 7.52 |
| Other Features | |
| Bluetooth 4.1 | Bluetooth 5.0 |
| GPS | GPS |
| NFC | -- |
| Fingerprint ID Scanner | Fingerprint ID Scanner |
| Accelerometer, Compass, Gyroscope, Light Sensor and Proximity Sensor | Accelerometer, Gyroscope and Proximity Sensor |
| FM Radio | FM Radio |
Comparison review
Galaxy M21 is better than the Galaxy J7 (2017), with an 84.1 score against 73.5. Even though the Galaxy M21 is a lot newer than the Galaxy J7 (2017), it is just a bit heavier and thicker. Both of these phones include Android OS, but Galaxy M21 has older 11 version while Galaxy J7 (2017) has Android 9.0 Pie version.
Galaxy M21 has a little more vivid display than Samsung Galaxy J7 (2017), because it has a bigger display, a little bit better screen pixel density and a slightly higher 1080 x 2340px resolution. Galaxy M21 has a very superior memory capacity to store more games and applications than Samsung Galaxy J7 (2017), because it has 48 GB more internal storage capacity and an external memory slot that holds up to 512 GB.
Galaxy M21 features a bit superior processing unit than Samsung Galaxy J7 (2017), and although they both have 8 CPU cores, the Galaxy M21 also has a greater amount of RAM. The Galaxy M21 has a superior battery life than Galaxy J7 (2017), because it has a 6000mAh battery size against 3600mAh. The Samsung Galaxy M21 has a much better camera than Galaxy J7 (2017), because although it has a tinier aperture which is not good for low light images and videos, it also counts with a back camera with a lot better resolution and a much higher 3840x2160 video definition.
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