Difference between Mifare 1K and Mifare 4K

• Mifare 1K – 1 KB of memory, standard choice for access control systems and simpler ID solutions. Enough for authorizations and identity.
• Mifare 4K – 4 KB memory, used in more advanced systems that require more data, such as payment solutions, loyalty programs or multifunctional access cards.

In short: Choose 1K for simple access management, and 4K if you need to store more information or combine multiple functions in the same card. If you are unsure what you are using today, 4K is a safer option because it has more memory.

Here is a guide that describes how to choose the right tag.