books
Open Library
An open, editable catalogue of books, editions, and authors run by the Internet Archive, holding records for over 40 million editions and works, with links to borrowable copies. You can search by title or look up a specific ISBN through its keyless API, or browse the catalogue on the web. It is a solid general-purpose stop for bibliographic details and for finding where a book can be read or borrowed.
Why it’s useful & how it works
Open Library's strength is breadth: it aims to hold a record for every book ever published, making it the first place to check for bibliographic details on any edition. You can search by title, author, or ISBN on the website, and its API accepts ISBN or Open Library identifiers for programmatic lookups. Where the Internet Archive holds a borrowable scan, Open Library links directly to it, so you can move from a catalogue record to a readable copy in one click.
What’s inside
Over 50 million edition records covering works in virtually every language and era, with borrowable digital copies available for a substantial share of them.
API access
https://openlibrary.org/api/books?bibkeys=ISBN: <isbn>&format=json&jscmd=data ; search https://openlibrary.org/search.json?q= ...
What we measured
Our own probes, not the archive’s own claims. Re-run periodically; every reading below is dated.
Reachability
- Direct request
- Responded HTTP 200 1.1 s
- Through a datacenter proxy
- Responded HTTP 200 1.2 s
- API books, direct
- Responded HTTP 200 571 ms
- API books, through a proxy
- Responded HTTP 200 1.4 s
- Search JSON, direct
- Responded HTTP 200 404 ms
- Search JSON, through a proxy
- Responded HTTP 200 803 ms
Did a real search return anything?
Returned results · 3370 results for the sample query · median 1.1 s · stable across runs
Sample query: Frankenstein; or, The Modern Prometheus
Benchmark coverage
Found 10 of 10 test items (100%) in the Books cluster. Median response 360 ms.
By how well known the item is: 4/4 well-known, 4/4 mid, 2/2 obscure .
One item it found: Frankenstein; or, The Modern Prometheus
Reachability measured 2026-08-22. Search checked 2026-08-22. Benchmark run 2026-08-22.
Access
Programmatic API access (a key may be required, see the API tag).