EPUB Splitter
Split a large EPUB ebook into smaller valid EPUBs by word count — ideal for NotebookLM's 5000-word source limit. Cuts only between paragraphs, never mid-sentence.
How it works
- Choose your
.epubfile and pick words per part (5000 is preset for NotebookLM). - Click Split EPUB — the book is read in chapter order and divided at paragraph boundaries.
- Download each part as a valid EPUB, or grab everything as one ZIP.
Features
Never mid-sentence
Splits happen only between paragraphs, so meaning and page flow stay intact.
Valid EPUB output
Each part is a real, openable EPUB with proper metadata, table of contents, styles and images.
Chapter-aware
Every part shows which chapters it covers, so you can keep track across uploads.
Fully private
Your ebook is processed locally. Nothing is uploaded or stored anywhere.
Your ebook never leaves your device
The EPUB is unzipped, split and rebuilt with JavaScript directly in your browser.
Frequently asked questions
Why split an EPUB at 5000 words?
Tools like Google NotebookLM accept up to about 5000 words per uploaded source. Splitting a large ebook into 5000-word parts lets you upload the whole book as multiple sources without losing content.
Will chapters and sentences stay intact?
Yes. The splitter only cuts between paragraphs — never in the middle of a sentence. Chapter titles, headings and formatting are preserved in every part, and very long chapters are split at paragraph boundaries.
Are images and styling preserved?
Yes. Images referenced by each part are embedded in that part, and the book's stylesheets and fonts are carried over, so every split file looks like the original.
Is my ebook uploaded to a server?
No. Your EPUB is opened, split and rebuilt entirely in your browser with JavaScript. The file never leaves your device.
What if a single chapter is longer than the word limit?
The splitter will divide the long chapter at paragraph boundaries so each part stays near your chosen word count, without ever cutting a sentence in half.