Access Control Bit-Format Decoder (Beta) — Red Team LLC

Access Control Bit-Format Decoder BETA

A student-friendly tool by Red Team LLC • 35 formats • LF=125 kHz | HF=13.56 MHz • parity checks • hex→bits

Legend & Quick Glossary

  • Frame: the full line of bits (0/1) the card sends. Wiegand-26 has 26 bits total.
  • Facility (Site): 8-bit number telling you which building/system. Not globally unique.
  • Card ID: 16-bit number identifying the specific card within that facility.
  • Parity bits: quick error checks at both ends of the frame.
    • Even parity (bit 0): include this bit + bits 1–12 → total 1s is even.
    • Odd parity (bit 25): include this bit + bits 13–24 → total 1s is odd.
  • UID/CSN formats: some cards (e.g., MIFARE/iCLASS) expose a chip serial instead of Facility/Card ID fields.
Evenbit 0
Facilitybits 1–8
Card IDbits 9–24
Oddbit 25
Even parity covers bits 1–12
Odd parity covers bits 13–24
Even parity Odd parity Facility Card ID / UID
Pick a format, or type the bitstream and we’ll suggest formats by length.
Select a format to see details.
Decoded Information

Enter bits (or hex) to decode.

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