ISBN Finder & Book Search
Search millions of books by title, author, or keyword. Or look up any book by ISBN-10 or ISBN-13 to get cover image, description, subjects, and links. Free, no account needed.
The ISBN Finder and Book Search tool is a free, browser-based lookup that finds a book by ISBN, title or author using the Open Library catalogue run by the Internet Archive. It returns the edition details, cover and publication year in seconds, with no account and no tracking.
How the Book Search Tool Works
This free online book finder connects to the Open Library API, maintained by the Internet Archive. Open Library catalogs over 20 million book editions contributed by libraries, publishers, and volunteers worldwide. When you search by title, author, or keyword, the tool queries Open Library's full-text search API and returns the most relevant matches with cover images, author names, and first publication year. No API key is required and all searches are completely free.
The tool has two search modes. Search Books accepts any query — you can type a book title, an author's name, a subject like "World War II history," or any combination. ISBN Lookup accepts any 10 or 13-digit ISBN and retrieves the exact edition, including the publisher, publication date, page count, and full subject list. This is useful for checking library holdings, comparing editions, or verifying publication details for citations.
ISBN Lookup and Classic Books
ISBN (International Standard Book Number) is a unique identifier assigned to every edition of every published book. ISBN-13 became the global standard in 2007, though older books still use 10-digit ISBNs. Both formats work with this tool. The "Random Classic" button randomly selects one of the world's most celebrated books — including Pride and Prejudice, 1984, Moby Dick, Don Quixote, and The Great Gatsby — and looks it up by its known ISBN, giving you a curated discovery experience every time you click.
Finding Books on Amazon and Goodreads
When you click any book, the detail view shows links to search for that title on Amazon and Goodreads. These are search links rather than direct product links, which means they always work regardless of regional availability or edition variations. Amazon's link helps you find purchasing options, while the Goodreads link shows community ratings, reviews, and reading lists. Your recent searches are saved as clickable chips using browser localStorage, so you can quickly return to books you looked at without re-typing. Last updated: August 2026, using the Open Library API v3.
Where to Find an ISBN and How to Check It Is Valid
On a printed book the ISBN sits in two places: above the barcode on the back cover, and on the copyright page just behind the title page. Ebooks usually list it in the front matter or on the store's product details. If a lookup returns nothing, the number is very often mistyped rather than missing.
You can check an ISBN-13 before you search it. Multiply each of the first 12 digits alternately by 1 and 3, add the results, and the check digit is whatever you must add to reach the next multiple of 10. Take 978-0-306-40615-7: the twelve digits sum to 93, the next multiple of 10 is 100, so the check digit is 7 — the number is valid. An ISBN-10 uses a different weighting and can end in the letter X, which stands for the value 10. To turn an ISBN-10 into an ISBN-13, drop its check digit, put 978 in front, and recalculate the check digit with the rule above. Prefixes are allocated by national agencies under the International ISBN Agency, which is why the group digit after 978 tells you the language or country the edition was registered in.
Two things regularly surprise people. Every format is a separate ISBN, so the hardback, paperback, ebook and audiobook of the same title each carry a different number — if you are checking a citation or a library holding, make sure you have the ISBN for the exact edition. And self-published or pre-1970 books may have no ISBN at all, since the system only came into general use in the early 1970s; for those, search by title and author instead.
ISBN, ASIN, OCLC or LCCN: Which Number Do You Actually Have?
A lookup that returns nothing is often a case of the right book and the wrong identifier, because four different numbering systems appear on the pages people copy from. This tool searches the Open Library catalogue, and the Open Library Books API states that it "supports ISBNs, LCCNs, OCLC numbers and OLIDs (Open Library IDs)." Here is how to tell them apart. An ISBN is 13 digits beginning 978 or 979, or 10 digits on older books, and is the one printed above the barcode. An OCLC number is a plain string of digits identifying a record in WorldCat, the shared catalogue used by libraries, and is what you will have copied if you came from a library catalogue page. An LCCN is a Library of Congress Control Number, usually a year prefix followed by a serial number, and appears on the copyright page of many US-published books. An OLID is Open Library’s own key and looks like OL123M for an edition or OL123W for a work. The odd one out is the ASIN: Amazon’s own identifier, which is not a library standard and is not in Open Library at all. For older print books the ASIN happens to be identical to the ISBN-10, so pasting it works by coincidence; for Kindle editions the ASIN starts with B0 and will never resolve here. If your number begins with B0, find the print edition’s ISBN and search that instead. Updated 2026-08-20.
Built-In ISBN Check-Digit Validator and ISBN-10 to ISBN-13 Converter
The ISBN Lookup tab now checks the number before it queries the catalogue. Paste an ISBN and the line under the box tells you three things immediately: whether it is a 10 or 13-digit ISBN, whether the check digit actually computes, and what the same book's other ISBN form is, with a copy button. A failed check digit means one digit is mistyped — the single most common reason a lookup returns nothing — and you learn that in the moment instead of after a dead search. The conversion uses the rule published by the International ISBN Agency: strip the ISBN-10 check digit, prefix 978, then recompute the modulo-10 weighted check digit. Because a 979-prefixed ISBN-13 has no 9-digit body to map back, the tool says so rather than inventing a number. If a valid ISBN returns no record, the lookup retries once with the other form automatically, since Open Library indexes some older editions under only one of the two. Updated 2026-08-28.
Privacy and Data
Your recent searches are stored only in your browser's localStorage and are never transmitted to Teamz Lab servers. The search queries themselves go to Open Library's public API, which is operated by the Internet Archive — a non-profit digital library committed to preserving universal access to knowledge. No personal account is needed, no email address is required, and no usage data is tracked by this tool.
Frequently Asked Questions
Is this book search tool free?
Yes, completely free. It uses the Open Library API from the Internet Archive, which requires no API key and no signup. You can search as many books as you like at no cost.
How many books are in the database?
Open Library catalogs over 20 million editions from libraries and publishers worldwide. It includes books in all languages, from ancient texts to modern publications.
How do I search by ISBN?
Switch to the 'ISBN Lookup' tab, paste any ISBN-10 or ISBN-13 number, and click Lookup. The tool fetches the exact edition from Open Library's book API and shows full details.
What does the Random Classic button do?
It picks a random famous book from a built-in list of classics (Pride and Prejudice, 1984, Moby Dick, etc.) and looks it up by ISBN, giving you a curated discovery experience.
Can I buy books directly from this tool?
This tool shows links to search for the book on Amazon and Goodreads. We don't sell books directly — we link to trusted external platforms where you can purchase or review them.
Are my searches private?
Your recent searches are stored in your browser's localStorage only. No data is sent to Teamz Lab servers. Queries do go to the Open Library API to fetch results, as with any online search.
Does this work for non-English books?
Yes. Open Library contains books in all languages. Search by title in any language or by ISBN for the specific edition you need.
Where is the ISBN on a book?
On a printed book the ISBN appears in two places: above the barcode on the back cover, and on the copyright page directly behind the title page. Ebooks normally list it in the front matter or in the store’s product details. If a lookup returns nothing, check for a mistyped digit first — that is far more common than a missing record.
Why does my ISBN lookup return no results?
Usually one of three reasons. The number is mistyped, so verify the check digit before searching. Or you have the ISBN for a different format — hardback, paperback, ebook and audiobook each get their own ISBN. Or the book genuinely has none: the system only came into general use in the early 1970s, and many self-published titles skip it. In the last two cases, search by title and author instead.
How do I convert an ISBN-10 to an ISBN-13?
Drop the ISBN-10 check digit, add the 978 prefix to the front, then recalculate the check digit: multiply the twelve digits alternately by 1 and 3, total them, and the check digit is whatever brings that total up to the next multiple of 10. An X at the end of an ISBN-10 means the value 10.
Can I search by Amazon ASIN?
No. An ASIN is Amazon\u2019s own identifier and is not held in Open Library, which this tool searches. For older print books the ASIN happens to be identical to the ISBN-10, so it works by coincidence. A Kindle ASIN starts with B0 and will never return a result \u2014 look up the print edition\u2019s ISBN and search that instead.
What is the difference between an ISBN, an OCLC number and an LCCN?
An ISBN identifies a specific published edition and is 13 digits beginning 978 or 979, or 10 digits on older books. An OCLC number identifies a record in WorldCat, the catalogue shared by libraries. An LCCN is a Library of Congress Control Number, normally a year prefix plus a serial number, printed on the copyright page of many US books. The Open Library API accepts all three, plus its own OLID keys such as OL123M.
Does this ISBN finder check whether my ISBN is valid?
Yes. As soon as you run a lookup, the line under the ISBN box reports whether the number is a 10 or 13-digit ISBN and whether its check digit computes correctly. A check-digit failure means one digit is mistyped, which is the most common reason a lookup returns nothing. The tool still runs the search so you can see for yourself, but it warns you first.
Can I convert an ISBN-10 to an ISBN-13 here?
Yes, automatically. Enter either form and the tool shows the equivalent other form with a copy button, using the International ISBN Agency rule: drop the ISBN-10 check digit, prefix 978, then recompute the modulo-10 weighted check digit. ISBN-13 numbers that start with 979 have no ISBN-10 equivalent and the tool says so instead of guessing. If a valid ISBN returns no record, the lookup retries once with the other form, because Open Library indexes some older editions under only one of the two.