| Sony Xperia U | ViewSonic ViewPad 4 |
| Manufacture | Sony | ViewSonic |
| Model | Xperia U | ViewPad 4 |
| Form factor | Block | Block |
| Weight | 110 gram | NA |
| Dimensions (HxWxD) | 112 x 54 x 12 | 121.00 x 66.00 x 11.00 |
| Operating System | Android | Android |
| Networks | 2G - 850/900/1800/1900 3G - 900/2100 | 2G - 800/850/1800/1900 3G - 900/2100 |
| HSCSD |  | |
| GPRS |  | |
| EDGE | | |
| UMTS | | |
| HSDPA | | |
| HSPA+ | | |
| WiMAX | | |
| LTE (4G light) | | |
| WLAN / Wi-Fi | | |
| Wi-Fi Hotspot | | |
| Wi-Fi Direct | | |
| SMS | | |
| MMS | | |
| | |
| HDMI out | | |
| USB port | | |
| MHL | | |
| Bluetooth | | |
| Bluetooth version | 3.0 | NA |
| DLNA | | |
| GPS | | |
| Glonass | | |
| ANT+ | | |
| IrDA | | |
| NFC | | |
| 3.5 mm audio connector | | |
| Camera | | |
| Camera resolution | 5 megapixel, autofocus, 16x digital zoom, face detection | 5 megapixel, autofocus |
| Image Stabilization | | |
| BSI sensor | | |
| Camera Flash/Light | | |
| Flash type | NA | NA |
| Video recording | | |
| Video capture resolution | 720p | NA |
| Second Camera | VGA (640 x 480) | VGA (640 x 480) |
| Display size | 3.5 inches | 4.10 |
| Touchscreen | | |
| Colour display | | |
| Number of colours | 16000000 | 16000000 |
| Display width | 480 | 480 |
| Display height | 854 | 800 |
| PPI | 279.9 | 227.55 |
| Second Display | NA | NA |
| CPU | 1 GHz dual core ST-Ericsson U8500 processor | 1 GHz Qualcomm MSM 8255 |
| GPU | DB8500 | NA |
| Memory | 512 MB. 4 GB storage. Expandable up to 32 GB using microSD card | 512 MB |
| Micro SIM | | |
| Dual SIM | | |
| MP3 | | |
| Ringtones / Music file format | MP3, AAC, WMF, WAV, OTA, OGG | MP3 |
| Java | | |
| Games | Yes | Yes |
| FM Radio | | |
| Battery | 1320 mAh | NA |
| Standby time (h) | 472 | NA |
| Talktime (m) | 396 | NA |
| Wireless Charging | | |
| Browser | Android HTML Webkit | Android HTML Webkit |
| Calendar | | |
| Voicedialing | | |
| IP Code | NA | NA |
| Predictive text | | |
| RSS reader | | |
| Voicememo | | |
| PC Synchronization | | NA |
| SyncML | | |
| Website | Website | Website |