Compare EPUB Files
Compare two EPUB files online, chapter by chapter. Choose rendered visual comparison or a structural text diff for tracking copy edits. Free, with no upload.
Files never leave your browser.
About EPUB Diff
Compares two EPUB ebooks chapter by chapter. Rendered pages draws each chapter as an image and marks pixel-level changes; Chapter text extracts the content and runs a structural diff.
How to use
- Drop or pick the left .epub file.
- Drop or pick the right .epub file.
- Set Compare as to Rendered pages or Chapter text under Options.
What this tool doesn't handle
- DRM-protected EPUBs cannot be read.
- Multimedia content embedded in chapters is not analyzed.
Frequently asked questions
Do my files ever leave my browser?
No. Every comparison runs locally in your browser. Nothing you paste, drop, or load is uploaded to a server; the tool keeps working even if you go offline after the page loads.
Is this tool free to use?
Yes. All DiffResolver tools are free, with no account, sign-up, or installation. Because processing happens on your device, there are no server-imposed usage limits.
How are EPUB books compared?
Chapter by chapter. Rendered pages draws each chapter and compares the pixels; Chapter text extracts the chapter text and runs a structural diff, which is better for tracking copy edits.
Can I compare DRM-protected ebooks?
No. DRM-protected EPUBs cannot be opened in the browser; only DRM-free files are supported.
Is there a file size limit?
No server limit applies, because nothing is uploaded. The memory of your device sets the practical limit. Above 10 MB for text, 40 MB for images, 100 MB for documents, or 500 MB for archives, the tool warns you that the work can be slow, but it never blocks the file.
Does this tool work offline?
Yes. The browser keeps a copy of the tool after the first visit, so a page you opened before still works without a network. You can also install DiffResolver as an app from the browser menu. Installation stays optional; the site works the same in a normal tab.
Where is my data stored?
Your files are stored nowhere. They stay in the memory of the page and are gone when you close the tab. Only what you save yourself stays in this browser: a snapshot, your tool options, and your theme. To remove it, open Settings and select Clear all local data.