Siemens AL21
| Type | Slide |
| Dimensions | 86.80 x 45.80 x 19.20 mm |
| Weight | 78.00 g |
| Display size | - |
| Display | Color / TFT 64k colors 130 x 130 px |
| Display protection |   |
| Additional display | |
| Protection of the secondary display | |
| Talk time (max.) | 2G: 300 min. (5.0 h) |
| Stand-by (max.) | 2G: 220 h. (9.2 days) |
| Standard battery | Li-Ion 600 mAhBuy powerbank
|
| Quick battery charging | |
| Wireless battery charging | |
| Internal memory | 1.5 MB |
| Memory cards | |
| Touchscreen | |
| DualSIM | |
| Other names | - |
| GSM frequencies | 900 1800 1900 |
| UMTS | |
| LTE standard | |
| CDMA | |
| Standard TD-SCDMA | |
| UMA | |
CAMERAS - BACK
CAMERAS - FRONT
SENSORS
| Accelerometer | |
| Proximity | |
| Light | |
| Magnetometer | |
| Gyroscope | |
| Barometer | |
| Altimeter | |
| Gravity | |
| Hall-effect | |
| Iris scanner | |
| Fingerprint scanner | |
| Thermometer | |
| Hygrometer | |
Data transfer
| xHTML | |
| WAP |  v1.2.1 |
| HSCSD | |
| HSUPA | |
| HSPA | |
| HSPA+ | |
| LTE DL | |
| LTE UP | |
| WIMAX+ | |
| GPRS | class 8 |
| EDGE | |
| Bluetooth | |
| HDMI | |
| WiFi | |
| WiFi frequencies | |
| WiFi Direct | |
| WiFi Display | |
| DLNA | |
| Miracast | |
| WiFi hotspot | |
| IrDA | |
| USB | |
| Beidou | |
| NFC | |
COMMUNICATION AND MESSAGING
| Call waiting | |
| Conferency | |
| Call forwarding | |
| Push To Talk | |
| Instant Messenger | |
| SMS | |
| EMS | v4.3 |
| MMS | |
| Dictionary | T9 |
| Swype | |
| e-mail client | |
| Hardware QWERTY keyboard | |
| RSS Reader | |
Multimedia
| Radio | |
| MP3 | |
| Stereo speakers | |
| Audio Jack | |
| HD Voice | |
| Polyphony | 32 voices |
| Ring composer | |
| Games | |
| Java | MIDP 1.0 |
| Videophone | |
PIM AND ADDITIONAL FUNCTIONS
| Watch | |
| Stopwatch | |
| Alarm | |
| Calculator | |
| Currency converter | |
| Organizer | |
| Calendar | |
| Flight mode | |
| SyncML | |
| Data and fax | |
| Screensaver | |
| Interchangeable covers | |
| Voice dial | |
| Speakerphone | |
| Recorder | |
| Vibrations | |