What is actually inside an EPUB
Rename an .epub to .zip, unpack it, and you will find a folder of XHTML files, a stylesheet or two, the cover image, and a manifest listing the reading order. There is also a navigation document — toc.ncx in older files, nav.xhtml in newer ones — which maps chapter titles to files.
This is the whole reason ebooks are pleasant to speed read. Every problem described in how to speed read a PDF exists because a PDF describes a printed page and the structure has to be guessed. An EPUB does not describe a page at all. It says "this is a paragraph, this is a heading, this is a footnote", and a reader can simply believe it.
What that means in practice
- Chapters are free. They come from the navigation document, not from guessing font sizes. So "pause at the start of each chapter" actually works, and so does jumping to chapter nine.
- No furniture. There are no running headers or page numbers to strip, because a reflowable book has no fixed pages.
- Paragraphs survive. Which matters more than it sounds: a slight pause at each paragraph break is most of what makes a long stream of words feel like prose instead of a ticker.
- Notes can be left out. Footnotes and endnotes are marked up as such, so they can be skipped instead of arriving mid-sentence.
Getting a file to read
Any EPUB you own works. In practice that means:
- Public domain books from Project Gutenberg and Standard Ebooks, which are free and generally well made — Standard Ebooks in particular produces unusually clean markup.
- Books you bought DRM-free, from a publisher's own store or a shop that sells unlocked files.
- Your own library, exported from a tool like Calibre.
What does not work is a book with digital rights management on it — a file from a store that locks it to one app. The contents are encrypted, and a browser cannot read them. That is a licensing fact, not a technical shortcoming, and no reader that respects the law will open one.
Your file stays on your device
Readly unpacks the EPUB in the browser, using the zip and XML tools every browser already has. There is no upload step, no server-side conversion, and no copy of your book anywhere but your own machine. A book is a personal object; a novel you are halfway through says more about you than most things you would think twice about uploading.
The practical consequence is that a large book loads in a second or two and works offline. The other consequence is that if you clear your browser, it is gone — which is the argument for saving your place to an account, and the reason we are building a library at all.
Reading a whole book this way
A 300-page novel is roughly 90,000 words. At 400 words per minute that is under four hours of pure reading time, which sounds like a weekend and is in fact a considerable stretch of concentration. Some things that help:
- One chapter at a time. Turn on the pause at chapter starts and let the book tell you where to stop. A chapter is a unit an author designed; a "session" is not.
- Fiction takes a different pace from non-fiction. Most people find they can run a novel faster than an argument, because narrative carries you and exposition does not.
- Turn on the paragraph pause. It costs a few seconds an hour and makes the text feel like writing.
- Do not fight the story. If you are re-reading a page, the answer is a lower speed, not more determination.
Is this really reading?
It is reading with one affordance removed: you cannot let your eye drift back a line. Everything else — recognising the words, hearing the sentence, forming the picture — happens as it always does. For a novel that you are reading to enjoy, most people find this fine at a moderate pace and irritating at a fast one, which is a good instinct to follow.
For anything you are studying, it is the wrong tool, and we would rather say so than sell you a reason to believe otherwise. The longer version of that argument is in does speed reading work?