ISBN check
GET /v1/check/isbn validates ISBN-10 (modulus 11, last digit may be X) or ISBN-13 (modulus 10). Hyphens and spaces are ignored.
This is not a live Nielsen, British Library, or Amazon lookup. A passing checksum does not prove the edition exists.
Try it
https://fetch.li/v1/check/isbn?number=9780306406157
Parameters
| Parameter | Required | Description |
|---|---|---|
number |
Yes | ISBN-10 or ISBN-13, hyphens optional |
Demo
GET endpoints work without an API key on the public demo tier (60 calls per hour per IP).
Try it
GET https://fetch.li/v1/check/isbn
Answer
Response