| General | |
| Manufacturer: | Palm |
| Model: | Zire 21 |
| Year: | 2003 |
| Operating system: | Palm OS 5.2 |
| Measurements | |
| Dimensions (mm): (width x height x thickness) |
74 x 112 x 16 |
| Weight (g): | 110 |
| Processor | |
| Processor Type: | Texas Instruments OMAP 311 |
| Clock Frequency (MHz): | 126 |
| Memory | |
| Random access memory (RAM) (MB): | 8 |
| Read-only memory (ROM) (MB): | 4 |
| Communications | |
| Other: | IrDA |
| Multimedia | |
| Screen Size: | 2.8 |
| Screen Resolution (px): | 160 x 160 |
| Speaker: | mono |
| Management and input | |
| Touchscreen: | resistive |
| Buttons: | physical buttons |
| Extension | |
| Additionally |