Here’s a detailed comparison of .epub, .mobi, .djvu, .md, and .pdf formats, including a textual breakdown and a summary table:

Text Comparison

EPUB (.epub)
- Pros:
  - Reflowable text adapts to any screen size (ideal for e-readers).
  - Supports interactive features (audio, video, annotations).
  - Open standard, DRM-friendly, and widely supported.
- Cons:
  - Complex layouts (e.g., textbooks, magazines) may render poorly.
  - Limited editing capability.
MOBI/AZW (.mobi)
- Pros:
  - Amazon Kindle-native format (optimized for Kindle devices).
  - Small file size due to compression.
- Cons:
  - Limited support outside Kindle (Amazon now prefers EPUB).
  - Fewer interactive features than EPUB.
  - No longer actively developed.
DjVu (.djvu)
- Pros:
  - Exceptional compression for scanned documents (smaller than PDF).
  - Ideal for archiving text+images (e.g., academic papers, manuals).
- Cons:
  - Niche support (requires specialized software).
  - Poor for reflowable text; mainly image-based.
Markdown (.md)
- Pros:
  - Human-readable plain text with simple syntax.
  - Easily editable, version-control friendly (e.g., GitHub).
  - Converts cleanly to HTML/PDF/EPUB.
- Cons:
  - No native rendering of complex layouts or images.
  - Not suitable for final publishing; requires conversion.
PDF (.pdf)
- Pros:
  - Preserves exact layout (fonts, images, vectors).
  - Universally compatible (print-ready).
  - Supports encryption, forms, and annotations.
- Cons:
  - Poor reflowability on small screens (requires zooming).
  - Editing requires specialized software.

Comparison Table

Feature	EPUB	MOBI	DjVu	Markdown (.md)	PDF
Primary Use	E-books (reflowable)	Kindle e-books	Scanned documents/books	Documentation (raw text)	Universal print/display
Reflowable Text	✅ Excellent	✅ Good	❌ No (image-based)	✅ Excellent (as source)	⚠️ Limited (fixed layout)
Image Handling	✅ Good	✅ Basic	✅ Exceptional compression	⚠️ Basic (external links)	✅ Excellent (high quality)
Interactivity	✅ Audio/video/annotations	⚠️ Basic annotations	❌ Minimal	❌ No	✅ Forms/links/annotations
Editing Ease	⚠️ Moderate (XML-based)	❌ Difficult	❌ Very difficult	✅ Easy (plain text)	❌ Difficult (specialized tools)
Compatibility	✅ Universal (except Kindle)	✅ Kindle-only	❌ Niche (DjVu viewers)	✅ Text editors	✅ Universal
File Size	Small-Medium	Small	✅ Very small (scans)	✅ Tiny	Large (high-res)
Best For	E-books, novels	Legacy Kindle content	Archiving scanned books/docs	Web docs, notes, coding	Print, forms, official docs

Key Recommendations

E-books: Use EPUB for broad compatibility (modern Kindles support EPUB).
Scanned Docs: DjVu offers superior compression, but PDF is more accessible.
Editing/Writing: Markdown for simplicity; convert to PDF/EPUB for sharing.
Print/Sharing: PDF remains the standard for fixed-layout documents.
Avoid MOBI: Amazon now uses EPUB; MOBI is outdated.

💡 Tip: Convert between formats using tools like Calibre (ebooks) or Pandoc (Markdown→PDF/EPUB). For DjVu, use WinDjView or DjVuLibre.