A Uniscoc Tiger T612 processor drives the device and is paired with 4GB RAM and 128GB storage. This can be expanded with micro SD card. HMD Global has stressed the usage of recycled materials on the Nokia T21 tablet. It is said to be made from 60% recycled materials, but the chassis is mostly plastic and aluminum. Like most tablets at this size, the battery is fairly large. The Nokia T21 has an 8,200mAh internal cell with support for 18W fast charging via USB-C.

The Nokia software skin is very similar to what Pixel owners will be accustomed to, with a lightweight build of Android 12 included. HMD Global has promised 2 full OS upgrades alongside three years of monthly security updates. The device listing also notes that the Nokia T21 is Android Enterprise Recommended for industry deployment.