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Validate credit card / IMEI (Luhn), bank account (IBAN mod-97) and book (ISBN-10/13) checksums. Everything runs in your browser.
Validate credit card / IMEI (Luhn), bank account (IBAN mod-97) and book (ISBN-10/13) checksums. Runs entirely in your browser.
Many identifiers carry a built-in check digit so that typos and transcription errors can be caught instantly, without contacting any system. Credit cards and IMEIs use the Luhn formula, international bank accounts use the IBAN mod-97 rule, and books use ISBN-10 or ISBN-13 checksums. This tool checks whether such a number is internally consistent according to its checksum.
Input:
4111 1111 1111 1111 (Luhn)
Output:
Valid Luhn checksum (16 digits).
Does a valid checksum mean the number is real?
No. It only means the number is internally consistent. A card or account number can pass Luhn or mod-97 yet not be issued to anyone.
What does the Luhn check cover?
Credit and debit card numbers, IMEI device identifiers, and some national IDs that use the same mod-10 scheme.
Which ISBN formats work?
Both ISBN-10 (with a possible trailing X) and the 13-digit ISBN-13. Hyphens and spaces are ignored.
Is anything uploaded?
No. Validation runs entirely in your browser.