All tools
25 decoders and reference tables for payments work, grouped by what they operate on. Every one runs in your browser, and nothing you paste is uploaded.
EMV chip
Decode the chip data a terminal exchanges with a card.
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EMV TLV Parser
Paste BER-TLV hex and get a decoded tag tree with EMV names, formats and nested templates.
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EMV Bit Field Decoder
Decode TVR, TSI, AIP, AUC, CID, CVM Results, Terminal Capabilities and the contactless qualifiers.
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Why Did It Decline? IAC vs TVR
Compare a TVR against the Issuer Action Codes to see exactly which bit forced the decline or the go-online.
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CVM List Parser
Break tag 8E into its X and Y amounts and the cardholder verification rules, in priority order.
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APDU Status Word Lookup
What 9000, 6A82, 6985 and the rest of SW1SW2 actually mean.
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AID Lookup
Application identifiers to scheme and product: A0000000031010 and friends.
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EMVCo QR Decoder
Decode a merchant-presented QR payload and verify its CRC.
ISO 8583
Pick apart authorisation and clearing messages.
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ISO 8583 Message Decoder beta
Paste a whole authorisation message and get every data element split out, interpreted and mapped to its bytes.
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ISO 8583 MTI Decoder
Split a 4-digit message type indicator into version, class, function and origin.
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ISO 8583 Bitmap Decoder
Turn a primary and secondary bitmap into the list of data elements present, and back again.
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ISO 8583 Data Element Reference
All 128 data elements with formats, lengths and the ones processors love to redefine.
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Decline Code Translator
DE 39 response codes in plain English, with what to actually do about each one.
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POS Entry Mode Lookup
What DE 22 and tag 9F39 mean, from chip to contactless to fallback to e-commerce, and why it changes your interchange.
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AVS & CVV Result Codes
Address and security-code check results in plain English, including which ones are fraud signals.
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STAN vs RRN vs ARN vs Auth Code
Four identifiers, constantly confused. What each one is, who sets it, and when it is unique.
Card numbers
Validate, identify and generate card numbers.
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PAN & BIN Validator
Luhn check, length rules and scheme range matching, including the overlaps nobody warns you about.
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Luhn Check Digit Calculator
Validate a number, compute a missing check digit, or find the typo that broke it.
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Track 1 & 2 Parser
Split magnetic stripe or chip-equivalent track data into its fields, including the service code.
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ARN Decoder
Break a 23-digit acquirer reference number into acquirer BIN, processing date and sequence.
Reference
Lookup tables you need three times a week.
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Currency Minor Units
ISO 4217 codes and exponents, with a converter so you stop getting JPY and KWD wrong.
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Country Code Lookup
ISO 3166-1 numeric to alpha, because EMV tag 9F1A and DE 19 speak in numbers.
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Hex, ASCII, EBCDIC & BCD Converter
Convert between every encoding a payments message uses, including EBCDIC, which mainframe acquirers still speak.
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MCC Lookup
Merchant category codes with descriptions and the special handling that comes with them.
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3DS ECI & Status Codes
ECI values differ between Visa and Mastercard. Here is the mapping, plus 3DS transStatus.
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Payments Glossary
ARQC, CDCVM, DPAN, PAR, TSP: the acronyms, without the circular definitions.