Build an EPUB eBook From Your Text
Book Metadata
Cover Image (optional)
Auto-resized to 1600x2400 (standard EPUB cover)
Theme
How to Make an EPUB File
- Choose your input format - Plain Text (with
===or***separators), Markdown (with# Heading), or HTML (with<h1>or<h2>). - Paste or type your content - Click a sample chip above to see an example, or paste your own text. The tool auto-detects chapters from headings.
- Fill in metadata - Title, author, language (40+ options), and optional publisher and description.
- Add a cover image - Optional. Click the cover area to upload a JPG or PNG. It is automatically resized to the EPUB standard 1600x2400 pixels.
- Pick a theme - Default, Serif (book-like), Modern (clean), or Compact (more text per page).
- Preview and generate - Click "Preview Structure" to see chapter list and stats, then "Generate EPUB" to build the binary file.
- Download the .epub - One click. The file is a valid EPUB 3.0 that opens in Apple Books, Google Play Books, Kobo, Calibre, Adobe Digital Editions, and (via Send to Kindle) on Kindle devices.
What is EPUB?
EPUB (Electronic Publication) is the international standard e-book format maintained by the W3C. It is a ZIP archive with a specific structure: an uncompressed mimetype file, a META-INF/container.xml pointer, an OEBPS/content.opf package document containing metadata and a manifest, an EPUB3 nav.xhtml navigation file, a legacy toc.ncx for older readers, and one XHTML file per chapter. EPUB files are reflowable - text automatically adapts to any screen size and user font preference. They support custom fonts, embedded images, navigation, table of contents, and rich metadata.
What Input Formats Are Supported?
- Plain Text - Paste any .txt content. Chapters are detected by lines containing only
===or***separators (3+ characters), or by sequences of 3+ blank lines. - Markdown - Use
# Headingfor chapter titles,## Subheadingfor sections,---for horizontal rules. Lists, bold, italic, links, code blocks, and blockquotes are all preserved. - HTML - Use
<h1>and<h2>for chapters. Standard HTML formatting (p, ul, ol, blockquote, code, em, strong, a) is preserved.
Frequently Asked Questions
Will my text be uploaded to a server?
No. The entire EPUB packaging pipeline runs in your browser using JSZip. Your text and cover image never leave your device. You can confirm by checking the Network tab in your browser DevTools - you will see zero outbound requests for the content. The only network requests are the JSZip library (cached after first load) and the Cloudflare Web Analytics beacon.
What input formats are supported?
Three modes: (1) Plain Text - paste any .txt content, chapters detected by separator lines (=== or ***) or by paragraph breaks; (2) Markdown - chapters detected automatically from # H1, ## H2, ### H3 headings and --- horizontal rules; (3) HTML - chapters detected from h1, h2 tags and hr separators. All three modes preserve your structure in the output EPUB.
What is EPUB and why should I create one?
EPUB (Electronic Publication) is the international standard e-book format maintained by the W3C. It is supported by Apple Books, Google Play Books, Kobo, Nook, Adobe Digital Editions, Calibre, and most e-readers including Kindle (via conversion or Send to Kindle). EPUB files are reflowable - the text automatically adapts to any screen size and user font preference. They support custom fonts, images, navigation, table of contents, and metadata. EPUB is the de facto standard for self-publishing.
Can I add a custom cover image?
Yes. Click the cover upload area to select a JPG or PNG image. It is automatically resized to 1600x2400 pixels (standard EPUB cover dimensions) and embedded in the output .epub file. If you do not upload a cover, a text-only cover with your book title and author is generated as an SVG.
How are chapters detected automatically?
Markdown mode: any line starting with # is treated as a chapter title. The depth (# vs ## vs ###) is preserved as h1/h2/h3 in the EPUB. Plain Text mode: lines consisting of only === or *** separators, or sequences of 3+ blank lines, mark chapter boundaries. HTML mode: h1 and h2 tags mark chapters. You can preview the detected structure before generating.
Why can't AI chatbots generate an EPUB file?
AI assistants like ChatGPT, Claude, and Gemini can write text and describe the EPUB format, but they cannot output a valid .epub binary file you can save and open in Apple Books or Kindle. An EPUB file is a ZIP archive with a specific structure: an uncompressed mimetype file, a META-INF/container.xml pointer, an OEBPS/content.opf package document, a nav.xhtml navigation file, and one XHTML file per chapter - all with precise relationships and metadata. AI text generation produces text, not binary archives. This tool runs the actual EPUB 3.0 packaging pipeline using JSZip in your browser.
Is the generated EPUB compatible with Kindle?
Yes - Kindle accepts EPUB files directly via the Send to Kindle service and personal documents, or you can use Amazon's KDP (Kindle Direct Publishing) to upload EPUB files. For older Kindles that require MOBI, use Calibre's command-line conversion (ebook-convert input.epub output.mobi) - it is a desktop install but free.
Are there any file size or content limits?
No hard limits imposed by this tool - JSZip can handle very large files in modern browsers. The practical limit is your device's available memory (typically 2-4 GB for the browser tab). Most novels (under 500,000 words) generate EPUB files under 5 MB. Cover images are automatically resized to 1600x2400 to keep the file small while looking sharp on high-DPI e-readers.
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