How to compress EPUB
- 1
Add your EPUB files
Drag and drop EPUB files onto the compressor, paste them, or click to browse. You can add several at once.
- 2
Pick a level or a target
Balanced is selected and suits most files. Choose Light to stay closer to the original or Strong for the smallest file, or set a target size or a percentage to reduce by.
- 3
Compress
Click Compress. Files are processed in an isolated cloud sandbox and are usually ready in seconds.
- 4
Download
Download each smaller EPUB, or everything at once as a ZIP.
What compression does to EPUB
Shrinks the embedded images and repacks the book at maximum compression; the text is untouched.
- Light
- Gentle: images are recompressed but stay close to the original; good for print.
- BalancedDefault
- The default: images are optimised for reading on screen, usually with no visible difference.
- Strong
- Smallest file: images are downsampled further; fine on screen, not for print.
Need an exact size?
Set a target size in the compressor above, or a percentage to reduce by, and each EPUB is compressed to land at or just under it.
EPUB · Electronic Publication
EPUB is the open standard e-book format with reflowable text, supported by Apple Books, Kobo, Google Play Books and Kindle (via Send to Kindle).
- Type
- eBook
- Extension
- .epub
- MIME
- application/epub+zip
- Best for
- e-books on almost every reader
Compressing EPUB: frequently asked questions
Smaller EPUB files, in seconds.
No sign-up, no watermark. Files are processed in an isolated sandbox and deleted automatically.
- Most conversions never leave your device
- Cloud files deleted automatically
- No watermarks