RFID and Smart Card Readers

Frequency decides which cards a reader can see

Cards and fobs work at one of two main frequencies. Low-frequency 125 kHz proximity cards simply broadcast an ID number and are common on older door systems. High-frequency 13.56 MHz cards, such as MIFARE and NFC, can hold more data and support stronger security. A reader must match the card's frequency, and dual-frequency readers read both. Check the card or fob for the standard it follows before choosing a reader, because look-alike cards are not compatible.

Desktop reader, printer module or loose tags

This category holds three kinds of product. Desktop readers connect to a PC by USB-A, USB-C or Bluetooth and are usually powered over the cable. Some readers are made for one host, such as a specific multifunction printer or tablet, and fit nothing else. Smart card readers for logging in use a contact slot and standard drivers, while key fobs and tags are sold in packs of 1 to 100. Match the reader to the credential type and the software.

Questions about RFID and Smart Card Readers

How do I tell whether my card is 125 kHz or 13.56 MHz?

Check the card markings or the access system's documentation. Proximity cards are usually 125 kHz, while MIFARE, NFC and many newer cards are 13.56 MHz. A dual-frequency reader avoids the guesswork if you have a mix.

Is an RFID reader the same as an NFC reader?

NFC is a form of 13.56 MHz RFID with a short range. An NFC reader can read compatible 13.56 MHz tags, but it will not read 125 kHz cards. Check the standards listed on the reader.

Does a reader write cards as well as read them?

Some do, but many are read-only and only report the card's ID number. Writing needs a read-write model and compatible cards. Check the description for read-write support if you plan to program tags.