There are a few key aspects of different nfc chips. Different antenna designs, different chip types, different memory capacities, different inlays (what the chip is attached to). Below is a brief explanation about what these aspects are and how they are set apart.

This is a good overall and reliable tag for a lot of applications with a larger antenna diameter, not as close together with the chip at the bottom.

Ideal for small size and high performance, these are very small tags with the antenna attaching at top center with close, tight coils.

This is a high performing, but large, credit card size antenna design. It is easy to see how it gets its name.

This looks like a racetrack tag, but is much smaller, with tightly packed coils and the chip located in the center.

Smaller than a mini-track and can be used on very small items.

Conclusion: Different antenna designs offer different characteristics in radio wave propagation and depending on the chip memory needs, some antenna designs cannot support the memory capacity. It all depends on the specific needs of the application.

Ultralight: Can hold 48 bytes (41 characters) - Limited text, but reads very fast with a good chip design.

Ultralight C: Can hold 148 bytes (132 characters) - Supports encryption and write protection, but reads slower.

NTAG 203: Can hold 144 bytes (132 characters) - Reads fast, holds a lot of characters with a good chip design. One of the best overall chips right now. This is what you will receive in your order.

1K: Can hold 752 bytes (256 characters) - Chip design runs slow, cannot write protect and expensive.