free tier · zero network
IBAN validator.
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ISO 13616 mod-97 in your browser. Detects Swiss QR-IBANs (institution ID 30000–31999). The same algorithm the paid POST /v1/iban/validate endpoint runs — see /docs/iban for the network version with the SIX Bank Master + EBA Clearing lookup.
Pure local — ISO 13616 mod-97 in your browser. Zero network calls. Algorithm at lib/iban.ts.
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Paste an IBAN to validate.