Credit card / IBAN validator
Validate credit card numbers with the Luhn algorithm and issuer detection, or IBANs with a mod-97 check and per-country length validation.
ⓘ Cette entrée est rédigée en anglais par les développeurs.
/tools/luhn handles two related checks behind one URL.
Card mode runs the Luhn algorithm (the mod-10 checksum every PAN uses) and, on success, identifies the issuer from the BIN range: Visa, Mastercard (including the new 2-series), American Express, Discover, JCB, Diners Club and UnionPay. Output masks the middle digits (453201••••••0366) so you can paste and share screenshots safely.
IBAN mode verifies the mod-97 checksum (rearrange + base-36-to-digits + remainder must equal 1) and cross-checks the length against the country code’s expected length — 78 countries covered, from AD24 to XK20. On success it extracts the BBAN (the country-specific account number).
Useful for sanity-checking test cards in a payment flow, for catching typos in customer-entered IBANs before they hit your backend, or just for double-checking a number someone read to you over the phone.