| HTC Desire Z | Siemens A55 |
| Manufacture | HTC | Siemens |
| Model | Desire Z | A55 |
| Form factor | QWERTY Slider | Block |
| Weight | 180 gram | 84.00 |
| Dimensions (HxWxD) | 119 x 60 x 14 | 101.00 x 44.00 x 21.00 |
| Operating System | Android | Other |
| Networks | 2G - 850/900/1800/1900 3G - 900/2100 | 2G - 900/1800 |
| 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 | NA | NA |
| DLNA | | |
| GPS | | |
| Glonass | | |
| ANT+ | | |
| IrDA | | |
| NFC | | |
| 3.5 mm audio connector | | |
| Camera | | |
| Camera resolution | 5 megapixel, autofocus, face detection, geo-tagging | NA |
| Image Stabilization | | |
| BSI sensor | | |
| Camera Flash/Light | | |
| Flash type | NA | NA |
| Video recording | | |
| Video capture resolution | NA | NA |
| Second Camera | NA | NA |
| Display size | 3.7 inches | 0.00 |
| Touchscreen | | |
| Colour display | | |
| Number of colours | 16000000 | NA |
| Display width | 480 | 101 |
| Display height | 800 | 64 |
| PPI | 252.15 | NA |
| Second Display | NA | NA |
| CPU | 800 MHz | NA |
| GPU | NA | NA |
| Memory | 512 MB. 1.5 GB storage. Expandable with microSD card | NA |
| Micro SIM | | |
| Dual SIM | | |
| MP3 | | |
| Ringtones / Music file format | MP3, AAC, AMR, OGG, M4A, WAV, WMA | Polyphonic |
| Java | | |
| Games | Yes | NA |
| FM Radio | | |
| Battery | 1300 mAh | Li-Ion 700 mAh |
| Standby time (h) | 430 | 250 |
| Talktime (m) | 590 | 300 |
| Wireless Charging | | |
| Browser | Android HTML Webkit | 1.2.1 |
| Calendar | | NA |
| Voicedialing | | NA |
| IP Code | NA | NA |
| Predictive text | | |
| RSS reader | | |
| Voicememo | | |
| PC Synchronization | | |
| SyncML | | |
| Website | Website | Website |