ISBN Validator API Reference

Overview

ISBN Validator works by analyzing ISBN-10 and ISBN-13 numbers, validating their checksum algorithms, and extracting information about the group, publisher, and title identifiers. Handles both formats with or without separators.

Endpoint

One host, one path per API. The block below shows this call in four languages; every one of them is the same HTTP request. Making requests covers the timeouts, retries and parameter rules that apply to all of them. The SDKs wrap the same call in a typed client.

GEThttps://api.apiverve.com/v1/isbnvalidator

curl "https://api.apiverve.com/v1/isbnvalidator?isbn=978-0-306-40615-7" \
  -H "x-api-key: your_api_key_here"

const res = await fetch('https://api.apiverve.com/v1/isbnvalidator?isbn=978-0-306-40615-7', {
  headers: { 'x-api-key': 'your_api_key_here' },
});

if (!res.ok) throw new Error(`${res.status} ${await res.text()}`);

const { data } = await res.json();
console.log(data);

import requests

res = requests.get(
    "https://api.apiverve.com/v1/isbnvalidator?isbn=978-0-306-40615-7",
    headers={"x-api-key": "your_api_key_here"},
    timeout=15,
)
res.raise_for_status()

print(res.json()["data"])

package main

import (
	"fmt"
	"io"
	"net/http"
)

func main() {
	req, _ := http.NewRequest("GET", "https://api.apiverve.com/v1/isbnvalidator?isbn=978-0-306-40615-7", nil)
	req.Header.Set("x-api-key", "your_api_key_here")

	res, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()

	out, _ := io.ReadAll(res.Body)
	fmt.Println(string(out))
}

Replace your_api_key_here with the key from your dashboard. When the inputs arrive as a list rather than one at a time, batch requests run up to 200 of them through this same API in a single call.

Authentication

Send your key in the x-api-key header. That is the only auth step — there is no token exchange and no per-endpoint scope to configure. Authentication covers creating, rotating and revoking keys.

401 is the only auth verdict

A 401 means the key is missing, invalid or expired. A 403 means the key is valid but not permitted here — blocked by a key restriction or an IP allow-list. Running out of credits is a 429.

Parameters

Sent in the query string. Premium parameters are accepted on every plan but only take effect on plans that include them.

Parameter	Type	Description
`isbn`Required	string	The ISBN number to validate (ISBN-10 or ISBN-13, with or without separators)

Response

Every API returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape. Response format covers the envelope, the other output formats and how premium fields are withheld.

Sample response

{
  "status": "ok",
  "error": null,
  "data": {
    "valid": true,
    "isbn": "978-0-306-40615-7",
    "type": "ISBN-13",
    "normalized": "9780306406157",
    "formatted": "978-0-306-40615-7",
    "checksum_valid": true,
    "prefix": "978",
    "group": "0",
    "publisher": "306",
    "title": "40615",
    "check_digit": "7",
    "error": null
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Field	Type	Example	Description
`valid`	boolean	`true`	Whether the ISBN is valid
`isbn`	string	`"978-0-306-40615-7"`	Normalized ISBN number
`type`	string	`"ISBN-13"`	ISBN format (ISBN-10 or ISBN-13)
`normalized`	string	`"9780306406157"`	The ISBN with hyphens and spaces removed
`formatted`Premium	string	`"978-0-306-40615-7"`	ISBN with proper hyphenation
`checksum_valid`	boolean	`true`	Whether the check digit matches the rest of the number
`prefix`	string	`"978"`	GS1 prefix, 978 or 979 for a 13-digit ISBN
`group`	string	`"0"`	Registration group, identifying the country or language area
`publisher`	string	`"306"`	Publisher element of the ISBN
`title`	string	`"40615"`	Title element, identifying the edition within the publisher
`check_digit`Premium	string	`"7"`	Check digit value
`error`	object	`null`	Why the ISBN was rejected; null when it is valid

Errors

Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change. Error handling covers the full status list and which of them are worth retrying.

Status	Meaning	What to do
`400`	Input was rejected	Read `error`; it names the parameter.
`401`	Key missing or invalid	Check the header name and the key value.
`403`	Key valid, but not permitted	A key restriction or IP allow-list; see key scoping.
`429`	Rate limited, or out of credits	Read `error` to tell them apart; see rate limits.

Use cases

Book Cataloging: Validate ISBNs when adding books to library catalogs or inventory management systems
E-commerce: Verify ISBN accuracy in book listings on e-commerce platforms to prevent listing errors
Publishing: Validate ISBNs during book registration and publishing workflows to ensure correct formatting
Data Quality: Check ISBN validity in book databases during data cleaning and migration projects

Other ways to use ISBN Validator

Set up ISBN Validator on APIVerve, or reach the same source a different way. Your APIVerve account and credits work on all of them — one key, one balance.

Give it to an AI agentConnect over MCP and your agent calls it as a native tool — Claude, Cursor, ChatGPT.VerveKit →Reference →

Use it in Google Sheets or ExcelA =VERVE() formula fills a column — no script, no export, recalculates in place.VerveSheets →Reference →

ISBN Validator