Convert Ebooks to EPUB API - Professional EPUB 3.0 Generation

Generate valid EPUB 3.0 ebooks from structured content with cover pages, table of contents, multilingual support, and 7 templates. Same input format as the PDF API — instant generation.

What can you do?
Valid EPUB 3.0 Output

Generate reflowable EPUB ebooks with proper OPF metadata, NCX table of contents, XHTML chapters, and embedded cover images. Compatible with all major ebook readers.

7 Professional Templates

Choose from Modern Novel, Elegant Novel, Academic Paper, Business Report, Cookbook, Travel Guide, or Technical Manual — each with unique styling.

21+ Languages

Auto-translated TOC headings, chapter numbers, and copyright text. From English to Bulgarian, German, Japanese, Arabic, and more.

99.9 % Uptime
Response
20 req/s
2 Credits / request

Convert to EPUB

POST https://api.yeb.to/v1/ebooks/epub/convert-from-file
Parameter Type Req. Description
api_key string Yes Your API authentication key (send in Authorization header or as parameter)
file_url string Yes Public URL to JSON file containing book data (metadata, chapters, options)
Same input as PDF API. Use the exact same JSON structure as the Ebooks to PDF API. Simply change the endpoint URL to get EPUB output instead of PDF.

JSON File Structure

Your JSON file at file_url should contain:

Parameter Type Req. Description
template string Yes Template name: modern-novel, elegant-novel, academic-paper, business-report, cookbook, travel-guide, technical-manual
metadata object Yes Book metadata (title, author, etc.)
metadata.title string Yes Book title
metadata.author string Yes Author name
metadata.language string Optional Language code (e.g., en, bg, de). Affects TOC heading, chapter numbering, copyright text. Default: en. Supports 21+ languages.
metadata.description string Optional Book description (embedded in EPUB metadata)
metadata.year integer Optional Publication year (default: current year)
metadata.publisher string Optional Publisher name
metadata.isbn string Optional ISBN number (added as dc:identifier in OPF)
metadata.subtitle string Optional Book subtitle (shown on title page)
metadata.series string Optional Book series name (shown on title page)
metadata.cover_image string Optional Cover image URL (downloaded and embedded in EPUB)
chapters array Yes Array of chapter objects (max: 100)
chapters[].title string Yes Chapter title
chapters[].subtitle string Optional Chapter subtitle
chapters[].content string Yes Chapter content (plain text or HTML). Paragraphs separated by \n\n are auto-wrapped in <p> tags.
options object Optional Customization options
options.include_cover boolean Optional Include cover page if cover_image provided (default: true)
options.include_copyright boolean Optional Include copyright page (default: true)
options.font_size string Optional Base font size, e.g., 12pt (default: 12pt)
options.line_height string Optional Line height, e.g., 1.6 (default: 1.6)
texts object Optional Override auto-translated texts (copyright_text, publisher_text, chapter_number_format, toc_title, etc.)

JSON File Example

1. Create book.json on your server:
{
  "template": "elegant-novel",
  "metadata": {
    "title": "The Great Gatsby",
    "author": "F. Scott Fitzgerald",
    "subtitle": "A Novel of the Jazz Age",
    "description": "A story of decadence and excess...",
    "year": 1925,
    "publisher": "Charles Scribner's Sons",
    "isbn": "978-0-7432-7356-5",
    "language": "en",
    "cover_image": "https://example.com/gatsby-cover.jpg"
  },
  "chapters": [
    {
      "title": "Chapter I",
      "content": "In my younger and more vulnerable years...\n\nAnd, after boasting this way..."
    },
    {
      "title": "Chapter II",
      "content": "About half way between West Egg and New York..."
    }
  ],
  "options": {
    "font_size": "12pt",
    "line_height": "1.6",
    "include_copyright": true
  }
}
2. Upload to your server (e.g., https://yourdomain.com/books/book.json)
3. Call the API:

Integration Examples

curl -X POST https://api.yeb.to/v1/ebooks/epub/convert-from-file \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"file_url": "https://yourdomain.com/books/book.json"}'
const response = await fetch('https://api.yeb.to/v1/ebooks/epub/convert-from-file', {
  method: 'POST',
  headers: {
    'Authorization': 'Bearer YOUR_API_KEY',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    file_url: 'https://yourdomain.com/books/book.json'
  })
});
const result = await response.json();
console.log(result.epub_url);
$response = Http::withHeaders([
    'Authorization' => 'Bearer YOUR_API_KEY'
])->post('https://api.yeb.to/v1/ebooks/epub/convert-from-file', [
    'file_url' => 'https://yourdomain.com/books/book.json'
]);
$epub_url = $response->json()['epub_url'];
import requests

headers = {
    "Authorization": "Bearer YOUR_API_KEY",
    "Content-Type": "application/json"
}
payload = {
    "file_url": "https://yourdomain.com/books/book.json"
}
r = requests.post('https://api.yeb.to/v1/ebooks/epub/convert-from-file', json=payload, headers=headers)
print(r.json()['epub_url'])

Response Examples

{
  "success": true,
  "epub_url": "https://yeb.to/storage/ebooks/epub/epub_abc123.epub",
  "epub_size": 5772,
  "template": "elegant-novel",
  "chapters": 3,
  "generated_at": "2026-02-18T14:30:00+02:00",
  "response_code": 200,
  "response_time_ms": 12
}
{
  "error": "Metadata field 'title' is required",
  "response_code": 400,
  "response_time_ms": 5
}

Response Codes

CodeDescription
200 SuccessRequest processed OK.
400 Bad RequestInput validation failed.
401 UnauthorizedMissing / wrong API key.
403 ForbiddenKey inactive or not allowed.
429 Rate LimitToo many requests.
500 Server ErrorUnexpected failure.
EPUB 3.0 Standard

Generated EPUBs are fully compliant with the EPUB 3.0 specification:

  • Valid OPF package document with dc:metadata
  • NCX table of contents (EPUB 2 compat)
  • EPUB 3 navigation document (nav.xhtml)
  • XHTML chapters with template-based CSS
  • Embedded cover image (JPG, PNG, WebP)
  • Title page, copyright page, TOC
  • 21+ languages auto-translated
Same Input as PDF

Use the exact same JSON data for both PDF and EPUB generation. Simply switch the endpoint URL to get your preferred output format.

Convert to EPUB

ebooks/epub/convert-from-file 2.0000 credits

Parameters

API Key
body · string · required
File URL
body · string · required

Code Samples


                
                
                
            

Response

Status:
Headers

                
Body

                

List Templates

POST https://api.yeb.to/v1/ebooks/epub/templates
Parameter Type Req. Description
api_key string Yes Your API authentication key
Free endpoint! This endpoint costs 0 credits. Use it to discover available templates before generating.

Available Templates

Modern Novel

Clean, contemporary design. Drop-cap first letters, elegant typography.

modern-novel
Fiction, novels, short stories
Elegant Novel

Classic serif design with italic chapter titles and borders.

elegant-novel
Fiction, novels, multilingual
Academic Paper

Professional layout with bold headings and clear structure.

academic-paper
Research, academic, thesis
Business Report

Sans-serif corporate design with accent borders.

business-report
Business, reports, proposals
Cookbook

Recipe-friendly layout with warm colors.

cookbook
Recipes, cooking, food
Travel Guide

Compact sans-serif design with green accents.

travel-guide
Travel, guides, tourism
Technical Manual

Structured layout with shaded headers and monospace numbers.

technical-manual
Documentation, technical, manuals

Response Example

{
  "success": true,
  "templates": [
    {
      "slug": "modern-novel",
      "name": "Modern Novel",
      "description": "Clean, contemporary design...",
      "best_for": ["fiction", "novels", "short-stories"]
    },
    {
      "slug": "elegant-novel",
      "name": "Elegant Novel",
      "description": "Fully customizable elegant design...",
      "best_for": ["fiction", "novels", "multilingual"]
    }
  ],
  "total": 7,
  "response_code": 200,
  "response_time_ms": 8
}

Response Codes

CodeDescription
200 SuccessRequest processed OK.
400 Bad RequestInput validation failed.
401 UnauthorizedMissing / wrong API key.
403 ForbiddenKey inactive or not allowed.
429 Rate LimitToo many requests.
500 Server ErrorUnexpected failure.

List Templates

ebooks/epub/templates 0.0000 credits

Parameters

API Key
body · string · required

Code Samples


                
                
                
            

Response

Status:
Headers

                
Body

                

Convert Ebooks to EPUB API - Professional EPUB 3.0 Generation — Practical Guide

A hands-on guide to generating EPUB 3.0 ebooks from structured content: metadata, chapters, and templates. Same input format as the PDF API — just switch the endpoint to get reflowable EPUB output.

#What this API does

Send structured book content (metadata + chapters) and receive a valid EPUB 3.0 file with automatic table of contents, cover page, copyright page, and template-based styling. The output is reflowable — readers can adjust font size and layout on any device. Supports 21+ languages with auto-translated section headings.

Same input as PDF API. If you already use the Ebooks to PDF API, you can use the exact same JSON — just change the endpoint URL to get EPUB output instead.

#Endpoint

#POST https://api.yeb.to/v1/ebooks/epub/convert-from-file

  • Best for: Converting novels, articles, manuals, or any multi-chapter content into EPUB ebooks.
  • How it works: Pure PHP generation via ZipArchive — no external tools needed. XHTML chapters, OPF metadata, NCX + nav.xhtml TOC.
  • Output format: Valid EPUB 3.0 with NCX fallback for EPUB 2 readers.
  • Processing time: ~5-50ms depending on chapter count and cover image download.

#Quick start

Step 1: Create a JSON file with your book data:

{
  "template": "elegant-novel",
  "metadata": {
    "title": "My Book",
    "author": "Jane Doe",
    "language": "en",
    "description": "A wonderful story.",
    "cover_image": "https://example.com/cover.jpg"
  },
  "chapters": [
    {
      "title": "Chapter 1",
      "subtitle": "The Beginning",
      "content": "It was a dark and stormy night...\n\nThe wind howled through the trees."
    },
    {
      "title": "Chapter 2",
      "content": "The next morning brought sunshine and hope."
    }
  ]
}

Step 2: Upload to your server and call the API:

curl -X POST https://api.yeb.to/v1/ebooks/epub/convert-from-file \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"file_url": "https://yourdomain.com/book.json"}'

Step 3: Download the EPUB from the returned URL:

{
  "success": true,
  "epub_url": "https://yeb.to/storage/ebooks/epub/epub_abc123.epub",
  "epub_size": 5772,
  "template": "elegant-novel",
  "chapters": 2
}

#Available templates

TemplateStyleBest for
modern-novelSerif, drop-cap first letters, contemporaryFiction, novels, short stories
elegant-novelPalatino serif, italic chapters, bordered headingsFiction, novels, multilingual
academic-paperTimes, bold headings, left-aligned, cleanResearch, academic, thesis
business-reportSans-serif, blue accent borders, corporateReports, proposals, white papers
cookbookSerif, warm red accents, recipe-friendlyRecipes, cooking, food
travel-guideVerdana, green accents, compactTravel guides, tourism
technical-manualSans-serif, shaded headers, monospace numbersDocumentation, manuals

#Multilingual support

Set metadata.language to a 2-letter ISO code and the EPUB will automatically use translated text for section headings:

  • Table of Contents heading (e.g., "Съдържание" for Bulgarian)
  • Chapter numbering format (e.g., "Глава {n}" for Bulgarian)
  • Copyright text (e.g., "© {year} {author}. Всички права запазени.")

Supported: en, bg, de, fr, es, it, pt, ru, uk, pl, nl, tr, ja, zh, ko, ar, cs, ro, el, sr, hr.

#Generated EPUB structure

book.epub (ZIP archive)
├── mimetype                     # "application/epub+zip" (uncompressed)
├── META-INF/
│   └── container.xml            # Points to content.opf
└── OEBPS/
    ├── content.opf              # Package document (metadata + manifest + spine)
    ├── toc.ncx                  # NCX table of contents (EPUB 2 compat)
    ├── nav.xhtml                # EPUB 3 navigation document
    ├── style.css                # Template-based stylesheet
    ├── cover.xhtml              # Cover page (if cover_image provided)
    ├── titlepage.xhtml          # Title page
    ├── copyright.xhtml          # Copyright page
    ├── chapter_001.xhtml        # Chapter 1
    ├── chapter_002.xhtml        # Chapter 2
    ├── ...
    └── images/
        └── cover.jpg            # Embedded cover image

#When to use EPUB vs PDF

FeatureEPUBPDF
Reflowable text Yes Fixed layout
Reader font control Yes No
E-ink devices (Kindle) Ideal Usable
Print-ready No Yes
Fixed page numbers No Yes
Generation speed~5-50ms~2-5 seconds
File sizeSmall (5-50KB)Larger (500KB-5MB)

Frequently Asked Questions

We generate EPUB 3.0 files with an NCX fallback for EPUB 2 readers. The output is compatible with Apple Books, Calibre, Kobo, Google Play Books, and all major ebook readers.

Yes! The EPUB API accepts the exact same JSON structure (metadata, chapters, template, options) as the Ebooks to PDF API. Simply change the endpoint URL to get EPUB instead of PDF.

Seven templates: Modern Novel, Elegant Novel, Academic Paper, Business Report, Cookbook, Travel Guide, and Technical Manual. Each provides unique CSS styling optimized for ebook readers.

Set metadata.language to any of 21+ ISO codes (en, bg, de, fr, es, it, pt, ru, uk, pl, nl, tr, ja, zh, ko, ar, cs, ro, el, sr, hr). Section headings, chapter numbers, and copyright text are auto-translated.

Yes. Set metadata.cover_image to a public URL (JPG, PNG, WebP). The image is downloaded and embedded directly in the EPUB file as the cover page.

Each EPUB generation costs 2 credits. The templates endpoint is free (0 credits). Credits can be purchased in packages starting from $10.

EPUB generation is extremely fast — typically 5-50ms for books with up to 100 chapters. No external tools or containers are needed; everything is built in pure PHP.

Generated EPUB files are stored for 30 days and then automatically deleted. Download your file promptly or store it on your own CDN.

Yes. Every request, even those resulting in errors, consumes credits. This is because your credits are tied to the number of requests, regardless of success or failure. If the error is clearly due to a platform problem on our end, we will restore the affected credits (no cash refunds).

Contact us at [email protected]. We take feedback seriously—if your bug report or feature request is meaningful, we can fix or improve the API quickly and grant you 50 free credits as a thank you.

It depends on the API and sometimes even on the endpoint. Some endpoints use data from external sources, which may have stricter limits. We also enforce limits to prevent abuse and keep our platform stable. Check the docs for the specific rate limit for each endpoint.

We operate on a credit system. Credits are prepaid, non-refundable units you spend on API calls and tools. Credits are consumed FIFO (oldest first) and are valid for 12 months from the purchase date. The dashboard shows each purchase date and its expiry.

Yes. All purchased credits (including fractional balances) are valid for 12 months from purchase. Unused credits automatically expire and are permanently deleted at the end of the validity period. Expired credits cannot be restored or converted to cash or other value. Transitional rule: credits bought before 22 Sep 2025 are treated as purchased on 22 Sep 2025 and expire on 22 Sep 2026 (unless an earlier expiry was stated at purchase).

Yes—within their validity window. Unused credits remain available and roll over month-to-month until they expire 12 months after purchase.

Credits are non-refundable. Only buy what you need—you can always top up later. If a platform-side error causes a failed charge, we may restore the affected credits after investigation. No cash refunds.

Prices are set in credits, not dollars. Each endpoint lists its own cost—see the “Credits / request” badge above. You’ll always know exactly what you’re spending.
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