Open Library Search — Free Book Search API (No Key)

TL;DR

Open Library Search is a full-text book search API that indexes over 25 million titles from the Internet Archive's Open Library project. You can search by title, author, subject, or any keyword and get results with covers, edition counts, publication years, ISBNs, and availability information. The search uses Solr under the hood, supporting faceted search, pagination, and fielded queries. This is the primary discovery endpoint for the Open Library ecosystem.

Quick start: https://openlibrary.org/search.json?q=javascript&limit=1

No API key needed — just make a request!

How to Use This API

1. Simple Keyword Search

https://openlibrary.org/search.json?q=javascript&limit=3

2. By Author

https://openlibrary.org/search.json?author=Agatha+Christie&sort=new

3. By Subject

https://openlibrary.org/search.json?subject=space+exploration&limit=5

4. JavaScript — Search with Details

fetch('https://openlibrary.org/search.json?q=dune&limit=5')
  .then(r => r.json())
  .then(d => {
    console.log(`Found ${d.numFound} books`);
    d.docs.forEach(book => {
      console.log(book.title + ' by ' + (book.author_name || ['Unknown']).join(', '));
      console.log('First published:', book.first_publish_year);
    });
  });

5. Python — Get Books by Topic

import requests

resp = requests.get('https://openlibrary.org/search.json', params={
    'q': 'artificial intelligence',
    'limit': 10,
    'sort': 'rating'
})
data = resp.json()
for book in data['docs']:
    if book.get('ratings_average'):
        print(f"{book['title']} — ⭐ {book['ratings_average']:.1f}")

Try it: https://openlibrary.org/search.json?q=python&limit=3

Try This URL Now

API Details

API URL: https://openlibrary.org/search.json
Documentation: openlibrary.org/developers/api
Category: Education
Authentication: Not Required
Geographic Coverage: Global

Frequently Asked Questions

Do I need an API key?: No. Open Library's public JSON API requires no authentication. It is free for any use.
What search fields are available?: You can search by q (general), title, author, subject, place, person, publisher, isbn, and more. Combine with Boolean operators.
How do I get book covers?: Results include cover_i (cover ID). Construct the URL as: https://covers.openlibrary.org/b/id/{cover_i}-M.jpg (S/M/L sizes).
What sorting options exist?: Use sort parameter: rating, new, old, title, editions, or rating.
How do I paginate results?: Use page (1-based) with limit (default 100, max 1000). The response includes numFound and start for building pagination.
Can I filter by availability?: Yes, add &available=true to restrict results to books that are freely readable online through Open Library.

What You Can Build

Book discovery app with cover thumbnails and ratings
Personal library cataloging tool
Reading list generator by subject or author
ISBN barcode scanner lookup tool
Library catalog front-end for Open Library collection