Check whether an IBAN is valid using the official mod-97 checksum and the expected length for its country. Formats it for readability.
Validation uses the ISO 13616 mod-97 checksum, the same check banks use, plus the expected length for the country code. It confirms the number is well-formed, not that the account actually exists.
It runs the official mod-97 checksum from the ISO 13616 standard and, for known countries, confirms the IBAN is the right length. Together these catch typos and transposed digits, which is exactly what the checksum was designed for.
No. It means the number is correctly formed and passes the checksum. Only the receiving bank can confirm that the account actually exists and is active.
No. The check runs entirely in your browser and the number is never transmitted or stored.