AI Book Statistics 2026: What 3,511 AI-Written Books Show

Original dataset · Infinite Library · Snapshot 2026-09-06 · Catalog since October 2025 · Licence CC BY 4.0

Finished AI-written books are shorter than most people assume: the median book on Infinite Library is 15,627 words, 43.1% are novella-length, and only 3% reach 40,000 words. Romance is 28.7% of the catalog, chapters run about 4,256 words, and 94% of books are in English. These are counts over 3,511 finished books by 2,383 authors, computed read-only on 2026-09-06.

Key findings

1. The median finished AI-written book on Infinite Library is 15,627 words long; the mean is 17,878 and the longest is 208,843 words.
2. Almost half of finished books (43.1%) are novella-length (17,500–39,999 words); only 3.0% reach the 40,000-word novel threshold.
3. Romance is the largest genre at 28.7% of books with a genre, ahead of general fiction (12.8%), science fiction (11.2%) and fantasy (11.1%).
4. Fantasy books run longest (median 23,046 words) and business books shortest (median 5,038 words).
5. The median AI-drafted chapter is 4,256 words (interquartile range 2,786–5,642), squarely inside the 2,000–5,000-word range writing guides recommend.
6. 94% of finished books are in English; French (1.9%) and Spanish (1.2%) lead the other 31 languages recorded.
7. 2,383 distinct authors finished 3,511 books — about 1.5 books each — and made 2,498 of them public.
8. Across the 3,197 finished books with more than 500 words, the catalog holds 57.2 million words.
9. In the 30 days to 2026-09-05, writers started 210 books in Bindery, ran 1,505 writing turns, published 16 to storefronts and placed 19 print orders.

How long are AI-written books?

Over the 3,197 finished books with more than 500 words, the 10th percentile is 4,048 words, the median 15,627, the 75th percentile 25,454 and the 90th percentile 31,127. The distribution is heavily weighted to novella length — the natural size of a one-sitting draft — with a long thin tail up to 208,843 words.

Bands follow the SFWA/Nebula definitions. Want to know how many pages a given word count makes? Use the words-to-pages calculator.

Which genres do people write with AI?

3,140 finished books record a genre, across 29 genres and 122 subcategories. The median length differs by more than four times between the longest genre (fantasy) and the shortest (business).

How long is an AI-written chapter?

Of the 536 finished books that record a chapter count, the median has 2 chapters (mean 3.6; 10th–90th percentile 1–5), because most were drafted as a few long parts. Where both counts exist (326 books), the median chapter is 4,256 words, with half of all chapters between 2,786 and 5,642 words. That matches the 2,000–5,000-word chapter norm in our guides on chapter length and chapter count.

Which languages?

32 languages appear in total. Bindery can translate a finished book into 110 languages as a separate edition; see the book tools.

Publishing and reading

3,486 finished books carry an ISBN and 3,509 have a cover. Readers left 78 reviews across 73 rated books, averaging 4.64 out of 5. By year of creation, 936 books were finished in 2025 (from October) and 2,303 so far in 2026.

Bindery studio, last 30 days

Between 2026-08-07 and 2026-09-05, writers started 210 new books in Bindery, ran 1,505 writing turns, published 16 books to public storefronts and placed 19 print orders. The companion iPhone app holds a 4.9-star App Store rating from 41 ratings (version 5.7, 2026-09-05).

Methodology

• Source: the Infinite Library catalog database and Bindery's daily usage metrics, aggregated read-only on 2026-09-06. No individual book, author or reader is identified; every figure is a count, share, or distribution statistic.
• "Finished" means the book's generation completed (status completed or published). Drafts, paused and failed runs are counted in the database total only.
• Word-count statistics exclude 314 finished entries under 500 words (stubs and test runs) so that shares describe real books. Length bands use the SFWA/Nebula cut-offs (short story under 7,500; novelette to 17,499; novella to 39,999; novel from 40,000), with the novel range split at 70,000 and 100,000 words.
• Chapter figures cover only the books that record a chapter count (536) and, for words per chapter, both counts (326); most finished books were drafted as long parts rather than short chapters, which is why the median chapter count is low while the median chapter is long.
• Genre and language are as recorded on each book. Language labels were normalised (e.g. "en", "UK English" → English). Percentages are of the books carrying that field, not of all finished books.
• Bindery activity covers the 30 days before the snapshot from the studio's daily metrics; "books started" counts new projects, "writing turns" counts completed compose runs, "published" counts books that opened a public storefront, "print orders" counts paid print checkouts.
• The App Store rating is the US storefront value returned by Apple's public lookup API on the snapshot date.

Cite this page

Infinite Library. “AI Book Statistics 2026: What 3,511 AI-Written Books Show.” 2026-09-06. https://www.infinitelibrary.ai/research/ai-book-statistics. Data: data.json (CC BY 4.0).

Frequently asked questions

How long is a typical AI-written book?

On Infinite Library the median finished book is 15,627 words, which is novella length. A quarter of books are under 7,075 words and a quarter are over 25,454 words; only about 3% pass the 40,000-word novel threshold. Genre matters: fantasy books have a median of 23,046 words, business books 5,038.

What genres do people write with AI?

Romance leads with 28.7% of books that record a genre, followed by general fiction (12.8%), science fiction (11.2%), fantasy (11.1%) and young adult (7.5%). Non-fiction, children's books, horror, self-help and business books make up most of the rest across 29 genres and 122 subcategories.

How long are AI-generated chapters?

Among books that record a chapter count, the median chapter is 4,256 words and half of all chapters fall between 2,786 and 5,642 words. Most books in this catalog were drafted as a few long parts rather than many short chapters.

Where does this data come from?

From the Infinite Library catalog database and Bindery's daily usage metrics, aggregated read-only on 2026-09-06. Only counts and distributions are published; no book, author or reader is identified. The full methodology is on this page and the numbers are downloadable as JSON.

Can I reuse these statistics?

Yes. The dataset is published under a Creative Commons Attribution 4.0 licence: quote or reuse any figure with a link to this page as the source ("Infinite Library, AI Book Statistics, 2026-09-06").

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