EPUB
Electronic Publication
An open standard e-book format using XHTML, CSS, and images packaged in a ZIP container for reflowable content.
技術的詳細
File epub reduces storage and transmission size. DEFLATE (used in ZIP and gzip) combines LZ77 dictionary coding with Huffman coding. Brotli (RFC 7932) achieves 15-25% better compression than gzip for text content and is supported by all modern browsers for HTTP compression. Zstandard (zstd) offers tunable compression levels from fast (comparable to lz4) to high (comparable to LZMA). For files already in compressed formats (JPEG, MP3, ZIP), re-compression provides negligible benefit and may slightly increase file size.
例
```javascript
// Create ZIP archive in browser (using JSZip)
const zip = new JSZip();
zip.file('readme.txt', 'Hello World');
zip.file('data/report.csv', csvContent);
const blob = await zip.generateAsync({
type: 'blob',
compression: 'DEFLATE',
compressionOptions: { level: 6 },
});
saveAs(blob, 'archive.zip');
```
関連フォーマット
関連ツール
F
Format Identifier
M
MIME Type Lookup
B
Base64 Encoder / Decoder
U
URL Encoder / Decoder
H
HTML Entity Encoder / Decoder
M
Markdown to HTML Converter
Y
YAML ↔ JSON Converter
L
Line Ending Converter
D
Data URI Generator
H
Hex Dump Viewer
U
Unicode Escape Converter
F
File Size Converter
C
Character Set Analyzer
F
Format Comparison Guide
C
Conversion Guide