Proxmark3 is an open-source hardware tool for RFID research, analysis, security testing, protocol sniffing, tag cloning, and emulation. It operates across both low-frequency and high-frequency bands, providing a single platform for interacting with a wide range of contactless cards and tags including MIFARE, iCLASS, HID Prox, Hitag, Indala, and T55xx transponders.
The tool is built around an FPGA that handles direct RF signal demodulation and modulation, enabling raw waveform capture and decoding. It includes a cryptographic attack framework capable of recovering secret keys through nested, hardnested, and dictionary-based algorithms. A Lua scripting engine allows users to automate sequences of operations directly on the device, and the hardware supports multiple communication interfaces—USB serial, Bluetooth, UART, and MQTT—with the ability to switch between them without restarting. Standalone mode preloads compiled scripts into firmware so the device can operate independently of a host computer.
Beyond core identification and cloning, Proxmark3 supports detailed card memory operations, including file hierarchy navigation, value file management, and NDEF record writing. It can emulate both tags and card readers, execute contactless payment transactions for testing, and capture and decode raw RF signals. Additional capabilities include magic card manipulation with backdoor commands, Wiegand encoding and decoding, smart card communication via the ISO 7816 interface, and trace data export to PCAP for offline analysis. The repository provides a build system with support for custom installation paths and multi-platform firmware variants, along with optional feature toggles for GUI, Bluetooth, and Python.