ISBN validate & convert API

Validates ISBN-10 (mod-11) or ISBN-13 (GS1 mod-10), and converts between the two forms with the correct recomputed check digit. Answers 'Is this ISBN valid?', 'What is the ISBN-13 for this ISBN-10?'.

Price$0.04per request

MethodPOST

Route/v1/validate/isbn

StatusLive

MIME typeapplication/json

Rate limit120/minute

Cache0s public

isbnisbn-10isbn-13bookcheck-digitmod-11validateconvertbibliographic

API URLhttps://x402.hexl.dev/v1/validate/isbn

Integration docs

Example request

{
  "isbn": "978-0-306-40615-7"
}

Example response

{
  "valid": true,
  "reason": "Valid ISBN-13 (GS1 prefix 978, mod-10 OK).",
  "normalized": "9780306406157",
  "type": "ISBN-13",
  "checkDigit": {
    "expected": "7",
    "actual": "7"
  },
  "prefix": "978",
  "isbn10": "0306406152",
  "isbn13": "9780306406157"
}

Input schema

{
  "type": "object",
  "required": [
    "isbn"
  ],
  "properties": {
    "isbn": {
      "type": "string",
      "description": "ISBN-10 or ISBN-13 (hyphens allowed).",
      "examples": [
        "978-0-306-40615-7"
      ]
    }
  }
}

Output schema

{
  "type": "object",
  "additionalProperties": true
}