ATR Parser
Decode ISO/IEC 7816-3 Answer-To-Reset bytes — convention, format byte, interface bytes (TA/TB/TC/TD), historical bytes, and check byte (TCK). Pasteable from PC/SC, OpenSC, GP shell, or your reader logs.
Input
Decoded
Paste an ATR to see it parsed.
All parsing happens in your browser. No bytes are sent to a server.
What is an ATR?
The Answer-To-Reset is a sequence of bytes a smart card emits in response to a cold or warm reset. It tells the reader what protocol to use, the clock-rate / bit-rate adjustment, the supply voltage, and (optionally) some historical bytes that hint at the card’s identity. ATRs follow ISO/IEC 7816-3. The structure is: TS · T0 · (TA1 TB1 TC1 TD1) · (TA2 TB2 TC2 TD2) … · HistoricalBytes · TCK?
Spec
ISO/IEC 7816-3 — the canonical reference for ATR structure and protocol negotiation.