LF and HF Operations

Commands in this page run at the Proxmark3 client prompt, after connecting the device. Keep the client and firmware versions matched.

First Identification

Place one tag over the appropriate antenna:

lf search

For a high-frequency tag:

hf search
hf 14a reader

hf 14a reader is an ISO14443A identification command. Use the matching protocol group for other tag families. Tag discovery does not imply access to protected memory.

Command Groups

Group	Use
lf	LF protocol tools and discovery
lf t55xx	T55xx configuration and memory tools
hf 14a	ISO14443A
hf 14b	ISO14443B
hf 15	ISO15693
hf mf	MIFARE Classic
hf mfu	MIFARE Ultralight
hf felica	FeliCa

Run help or the group name to inspect the installed command tree. Use a command's -h help before providing arguments: historical product documentation may use syntax from older client revisions.

Independent LF Mode

Mode 2 provides the product's independent 125 kHz LF read/write workflow. Read the source using LF Read, replace it with a compatible writable destination, and use LF Write. Confirm the result by reading it again.

This mode does not replace the interactive client's protocol tools and does not establish support for every LF format or 134 kHz tag.

T55xx Diagnostics

Start with identification and readback:

lf t55xx detect
lf t55xx read -h
lf t55xx write -h

Block 0 controls the tag's modulation and bitrate. Record the detected configuration before editing it. A wrong configuration can make later discovery fail even when the chip is still writable. Use the installed client's exact argument syntax; do not copy old wr b 0 d ... forms without checking help.

The T55xx troubleshooting guide provides additional context. A wipe is a destructive reset, not a required diagnostic step.

Antenna and Connection Checks

If tags are not detected, confirm the mode, antenna position, antenna-board connection, and client / firmware compatibility. Use hw tune for diagnostics when supported by the build. A protocol command appearing in help does not guarantee that this hardware revision supports its required RF frequency or accessories.