Gutendex (Project Gutenberg) API
Free Project Gutenberg API with no key: search 75,000+ public domain ebooks with authors, subjects, download links and full text in multiple formats. Tested.
Endpoint tested and returned HTTP 200 on 2026-08-20
What is the Gutendex (Project Gutenberg) API?
Gutendex is a free, key-free API for searching Project Gutenberg's catalogue of more than 75,000 public domain ebooks, returning author, subject, language, download counts and direct links to the full text in several formats.
Project Gutenberg hosts the largest collection of free public domain ebooks, but its own site is awkward to query programmatically. Gutendex wraps the catalogue in a clean JSON API with proper search and filtering.
The `formats` object is the practical payoff: each book links directly to plain text, EPUB, HTML and Kindle versions. Because everything is public domain, you can download, redistribute and build on the full text without any licensing concern.
Quick facts
- Base URL
https://gutendex.com- Authentication
- No API key required.
- Rate limit
- No published hard limit; fair use expected.
- Pricing
- Free. All books are public domain.
- CORS
- Enabled — callable directly from browser JavaScript
- Official docs
- Read the docs
How to use the Gutendex (Project Gutenberg) API
Every request below was executed against the live API on 2026-08-20, and the response shown is the real body it returned — not an illustration.
1. Search public domain ebooks
GET https://gutendex.com/books/?search=austen
curl 'https://gutendex.com/books/?search=austen'const res = await fetch("https://gutendex.com/books/?search=austen");
if (!res.ok) throw new Error(`Request failed: ${res.status}`);
const data = await res.json();
console.log(data);import requests
res = requests.get("https://gutendex.com/books/?search=austen", timeout=20)
res.raise_for_status()
print(res.json()){
"count": 49,
"next": "https://gutendex.com/books/?page=2&search=austen",
"previous": null,
"results": [
{
"id": 1342,
"title": "Pride and Prejudice",
"authors": [
{
"name": "Austen, Jane",
"birth_year": 1775,
"death_year": 1817
}
],
"summaries": [
"\"Pride and Prejudice\" by Jane Austen is a novel published in 1813. It follows Elizabeth Bennet, who must learn to see past first impressions and hasty judgments. With five daughters and an estate that can only pass to male heirs, the Bennet family faces financial pressure to marry well. When wealthy Mr. Darcy arrives in their countryside neighborhood, his pride and Elizabeth's prejudice set the stage for misunderstandings, hidden truths, and unexpected revelations about character and love. (This is an automatically generated summary.)"
],
"editors": [],
"translators": [],
"subjects": [
"Courtship -- Fiction",
"Domestic fiction",
"England -- Fiction",
"Love stories",
"Sisters -- Fiction",
"Social classes -- Fiction",
"Young women -- Fiction"
],
"bookshelves": [
"Best Books Ever Listings",
"Category: British Literature",
"Category: Classics of Literature",
"Category: Novels",
"Category: Romance",
"Harvard Classics"
],
"languages": [
"en"
],
"copyright": false,
"media_type": "Text",
"formats": {
"text/html": "https://www.gutenberg.org/ebooks/1342Parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
books/ | path | Optional | Book search and listing. books/ |
search | string | Optional | Search author and title. austen |
languages | string | Optional | Comma-separated language codes. en,fr |
topic | string | Optional | Search subjects and bookshelves. adventure |
sort | string | Optional | popular, ascending or descending. popular |
page | integer | Optional | Page number. 2 |
Response fields
countinteger- Total books matching the query.
next / previousstring- Pagination URLs.
results[].idinteger- Project Gutenberg book id.
results[].titlestring- Book title.
results[].authorsarray- Authors with birth and death years.
results[].subjectsarray- Library subject classifications.
results[].formatsobject- Direct download URLs by MIME type — text, EPUB, HTML, Kindle.
results[].download_countinteger- Popularity signal.
What you can build with the Gutendex (Project Gutenberg) API
- Build a public domain ebook reader or library
- Source full text for natural language processing
- Create a classic literature discovery site
- Provide free reading material in an education app
Common errors and how to fix them
Empty results
The search matched nothing.
Fix: Search covers author and title only; use `topic` to search subjects and bookshelves.
Choosing a format
The formats object is keyed by MIME type.
Fix: Look for 'text/plain; charset=utf-8' for raw text, or 'application/epub+zip' for EPUB.
Slow responses under load
It is a free community service.
Fix: Cache results; the catalogue changes rarely.
Gutendex (Project Gutenberg) API — frequently asked questions
Is Gutendex free?
Yes, completely free with no API key. Every book it indexes is public domain.
Can I download the full text?
Yes. The `formats` object links directly to plain text, EPUB, HTML and Kindle versions, and public domain status means you can redistribute them freely.
How many books are available?
More than 75,000 titles from Project Gutenberg, across many languages though predominantly English.
How do I search by genre?
Use the `topic` parameter, which searches subjects and bookshelves. The `search` parameter only covers author and title.
Tools that pair with this API
Word Counter
Count words, characters, sentences, paragraphs and estimated reading time instantly. Free online word counter for essays, blogs and social media.
JSON Formatter
Format, beautify and minify JSON online with 2-space, 4-space or tab indentation. Sort keys alphabetically and catch syntax errors instantly — free and private.
Character Counter
Count characters with and without spaces in real time and check limits for Twitter/X, Instagram captions, meta descriptions and SMS messages.
Gutendex (Project Gutenberg) is an independent third-party service and is not affiliated with ByteTools or ByteVancer. Details on this page were verified on 2026-08-20; always check the official documentation before relying on this API in production, as terms and limits can change.