Here's a step-by-step guide to help you determine whether your key fob is NFC or RFID. These two are related technologies, but NFC is a type of HF (high-frequency) RFID with specific standards for mobile and short-range communication.
1. Check the Frequency
RFID comes in three main frequency ranges:
| Type | Frequency | Typical Use | Examples |
|---|---|---|---|
| LF RFID | 125–134 kHz | Access control, pets | EM4100 fobs, TK4100 |
| HF RFID / NFC | 13.56 MHz | Access control, transit, payment | MIFARE Classic, NTAG213, NFC-enabled fobs |
| UHF RFID | 860–960 MHz | Inventory, logistics | EPC Gen2 fobs |
How to tell:
If your fob works with smartphones via NFC apps, it's HF/NFC.
If it doesn't communicate with phones but works with older access readers, it may be LF or UHF RFID.
2. Try Scanning with a Smartphone
NFC-enabled phones (most modern iPhones and Android phones) can read NFC/HF fobs.
Download a free NFC reader app:
If the app detects the fob, it's NFC / HF RFID (13.56 MHz)
If the app cannot detect anything, it's likely LF or UHF RFID (non-NFC).
⚠️ LF and UHF fobs cannot be read by smartphones.
3. Look at the Fob or Packaging
Some fobs have chip markings or model numbers:
EM4100 / TK4100 → LF RFID
MIFARE, NTAG, DESFire → HF/NFC RFID
Sometimes, the packaging mentions "NFC-enabled" or the frequency (13.56 MHz).
4. Observe Reader Compatibility
If the fob works with standard door or gym readers that do not mention NFC, it may be LF.
If it works with smartphone-based systems or payment terminals, it's HF/NFC.
5. Use a Specialized RFID Reader
For full certainty, a multi-frequency RFID reader can detect:
LF 125 kHz
HF/NFC 13.56 MHz
UHF 860–960 MHz
This is the most accurate way to identify the frequency and type of your fob.
✅ Quick Rule of Thumb
Works with phone / NFC app → NFC (HF RFID)
Works only with traditional access reader → LF or UHF RFID
Small keychain fobs with metal coating → usually LF
Plastic keychain fobs with logos / printed chips → often HF / NFC