Check digits and structure for ISBN, UPC/EAN, VIN, ISSN, ORCID, ISIN, CUSIP, LEI and MAC addresses.
payments ON MAINNET (real money) · 9 live endpoints
| Endpoint | Price | What it answers |
|---|---|---|
GET /cusip-check | $0.02 | Validate a 9-character CUSIP security identifier check digit and split issuer and issue codes. |
GET /gtin-check | $0.02 | Validate a UPC-A, EAN-8, EAN-13 or GTIN-14 barcode check digit and name its format. |
GET /isbn-check | $0.02 | Validate an ISBN-10 or ISBN-13 check digit and convert between the two forms. |
GET /isin-check | $0.02 | Validate a securities ISIN check digit and split it into country code and national security number. |
GET /issn-check | $0.02 | Validate an ISSN (journal or serial number) check digit and format it with the hyphen. |
GET /lei-check | $0.02 | Validate a 20-character Legal Entity Identifier with the ISO 7064 mod 97-10 check and split its parts. |
GET /mac-parse | $0.02 | Parse a MAC address in any common notation: canonical forms, OUI, unicast or multicast, universal or local. |
GET /orcid-check | $0.02 | Validate an ORCID iD (researcher identifier) with its ISO 7064 check character and give the canonical form. |
GET /vin-check | $0.02 | Validate a 17-character vehicle VIN check digit and decode region, manufacturer code and model-year candidates. |
GET /catalog returns this list as JSON. Activity hub · uptime.
Identifier checks are computed locally from published check-digit algorithms. A valid check digit proves the identifier is well formed, not that it is issued, assigned or belongs to anyone. This tool does not validate payment cards, bank accounts or government IDs. Every paid response carries a disclaimer field.