EPUB acts as a reflowable eBook format that adjusts to different screen sizes and reading preferences.
Common Uses
Publishing digital books for e-readers
Creating responsive files for mobile reading
Distributing digital publications
EPUB Optimization FAQ
What is an EPUB file?
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EPUB (Electronic Publication) acts as a free and open eBook standard by the International Digital Publishing Forum.
Why does the same EPUB book look different on two devices?
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Because it is meant to. An EPUB is a package of structured text and styling that the reader lays out at your chosen font and size, so page count and line breaks are properties of the device, not of the book. Converting to a fixed-layout format freezes one particular rendering — good for printing, worse for reading on a phone. EPUB is the open ebook standard from the International Digital Publishing Forum, now maintained by the W3C.
Why does my purchased EPUB refuse to convert?
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Because it is encrypted. A store-bought EPUB is locked to an account, and the file a converter sees is ciphertext rather than a book — there is nothing to read until the store's software decrypts it for its own reader. Removing that protection is a legal grey area in many countries and is not something this site does. Files you made yourself, or downloaded DRM-free, convert normally. EPUB has no fixed pagination, so page numbers are meaningless, and complex layout — tables, equations, multi-column — degrades badly.
Does the table of contents survive converting an EPUB?
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Yes, wherever the target has somewhere to put it. Ebook formats store navigation as real structure — a list of chapter anchors that the reader turns into a jump menu — and that is carried between them. A fixed-layout export turns it into bookmarks instead, and a plain-text export loses it along with everything else structural. Chapter breaks themselves survive all three.
What if my EPUB is a scan rather than real text?
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Then nothing downstream can read it until OCR has run. A scanned page is a picture of words: it looks fine, and searching, copying or converting to an editable document all come back empty. Optical character recognition adds a real text layer over the image, after which the words are selectable and the conversion produces an actual document instead of a wrapper around a photograph.
Is the cover image kept when I convert an EPUB?
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It is, provided the book records one as the cover rather than merely having a picture on its first page. That distinction is why a converted book sometimes shows a blank placeholder in a library: the image is still inside the file, but nothing marks it as the cover, so the reader app displays nothing. It is metadata rather than content, and it can be set afterwards without touching the text.
Does an EPUB have fixed pages?
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No — content flows, and pages appear only when something decides on a page size. Change the font, the margins or the screen and the page numbering changes with it. That is why a page reference from an EPUB is unreliable, and why converting to a fixed-layout format is the step that makes page numbers mean something.
Who controls the EPUB format?
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Nobody, and that is the point of it. The specification is public, anyone may implement it without asking or paying, and no company can change the terms later — which is why archives, standards bodies and public institutions specify formats like this one for anything that still has to open in twenty years. The trade is not compatibility, which is excellent; it is that there is no vendor to call when some tool implements the spec badly.
What happens to my EPUB file after the conversion?
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It is deleted automatically. The upload and the converted result stay on our servers for about 24 hours, which leaves time to download the result, and are then removed by an automatic cleanup. The transfer runs over HTTPS in both directions. Nobody reads the contents, nothing is indexed, and nothing is passed to anyone else.
How long does converting an EPUB take?
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Usually seconds. Small files are effectively instant, and the cases that take real time are the ones doing real work: a long recording that has to be re-encoded frame by frame, a scanned document going through character recognition, or a very large batch. Where a conversion only rewraps or repackages the existing data it stays fast no matter how big the file is, because nothing is being decoded.
What is the best way to tackle EPUB files?
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Upload your file by dragging it onto the page or clicking to browse, choose the output format, then start the conversion. The converted file is ready to download when it finishes.
Is video operating on free?
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Yes, our converter is bypassing exception free for introductory use. No registration compulsory.
