Compress an EPUB file
Shrink an image-heavy book so it fits an email attachment or a Send-to-Kindle limit.
How to compress an EPUB
- 01 Choose your EPUBDrop the file above or tap to pick one from your device.
- 02 Pick a levelBalanced is the right answer for almost every book.
- 03 DownloadText is never touched — only the images are re-encoded.
What actually gets smaller
Nearly all of an oversized EPUB is picture data. Images are resized down and re-encoded as JPEG, which is where the savings come from.
Left completely alone. The words, markup and metadata in your book are byte-for-byte identical afterwards.
Questions
How much smaller will it get? ＋
An image-heavy book typically halves on Balanced. A text-only novel will barely change, because there was nothing to compress.
Will the pictures look worse? ＋
Slightly, on close inspection. Light is near-invisible; Maximum is noticeable but still fine for reading.
Is any image ever made bigger? ＋
No. If re-encoding would not shrink an image, the original is kept.
Are my files private? ＋
This tool runs entirely inside your browser — your file is never uploaded anywhere. It stays on your device, and closing the tab is all it takes to remove it.
Is it really free? ＋
Yes. Every tool, no size cap, no account. There is no paid tier and nothing is held back.