formats devices
EPUB vs PDF vs TXT: Which Format Should You Choose?
How the three common ebook formats differ in layout, size, device support and accessibility, and which one to download for the way you read.
Published 2026-10-28 · Updated 2026-10-28 · 9 min read
For almost everyone reading on a phone, tablet or e-reader, EPUB is the right choice: the text reflows to fit your screen, you can change the font size, and every major reading app except Kindle’s opens it directly (and Kindle accepts it through Send to Kindle). PDF is the right choice only when the page layout itself matters, as with facsimile scans, illustrated editions or anything you plan to print. TXT is the fallback that opens on any machine ever made, useful for search, quoting and very old or very limited devices, at the cost of all formatting. If you do not want to install anything, the HTML “read online” version of a book works in any web browser.
Reflowable versus fixed layout
The single biggest difference between the formats is whether the text reflows.
A reflowable file stores the text and its structure (chapters, headings, paragraphs, emphasis) and lets the reading device decide how to lay it out. Turn the phone sideways, make the font bigger, switch to a dark background, and the lines rewrap to fit. EPUB and TXT are reflowable.
A fixed-layout file stores pages. Each page has a set size and every word has a fixed position on it. That is what PDF does by default: a PDF of War and Peace is a stack of pages designed for a particular paper size, and a phone screen can only shrink or crop them. Zooming in means panning left and right across each line. On a desktop monitor or a large tablet this is tolerable; on a six-inch screen it is the main reason people give up on long PDFs.
EPUB 3 can also carry fixed-layout content for picture books and comics, but the public domain EPUBs you will meet on Project Gutenberg and similar sites are reflowable.
What each format is
EPUB is an open standard, originally from the International Digital Publishing Forum and maintained since 2017 by the W3C; the current version is EPUB 3.3. Under the hood an EPUB file is a zip archive containing HTML pages, a stylesheet, images and a table of contents, which is why it handles chapters, footnotes and embedded pictures well. Project Gutenberg usually offers two EPUB downloads per book, one with images and one without.
PDF was created by Adobe in the early 1990s and has been an ISO standard since 2008 (the current edition is ISO 32000-2, PDF 2.0). It was designed so that a document looks identical on every printer and screen. That is a virtue for forms, legal documents and typeset books, and a limitation for reading prose on small devices. Public domain PDFs come in two kinds: scanned page images from libraries and the Internet Archive, which are large and not always text-searchable, and “born digital” PDFs typeset from a clean text, which are small and searchable.
TXT is plain text: nothing but characters, usually encoded as UTF-8 today. There are no fonts, no italics, no images and no chapter navigation beyond scrolling or searching. Project Gutenberg has produced plain text since its start in 1971 and still offers a UTF-8 text file for nearly every book.
HTML deserves a mention because it is what “Read online” means on this site and on Project Gutenberg. A single web page holds the whole book, with images and chapter links. It needs no app, no account and no download; the browser you already have is enough.
Comparison table
| EPUB | TXT | HTML (read online) | ||
|---|---|---|---|---|
| Layout | Reflowable | Fixed pages | Reflowable, unformatted | Reflowable |
| Adjustable font size and margins | Yes | Zoom only | Depends on the app | Yes (browser zoom) |
| Keeps italics, headings, chapter list | Yes | Yes (as drawn on the page) | No | Yes |
| Images | Yes (optional) | Yes | No | Yes |
| Typical size for a novel | Hundreds of KB to a few MB with images | From under 1 MB (typeset) to tens of MB (scans) | Usually well under 1 MB | Comparable to EPUB |
| Phone and tablet reading apps | Apple Books, Google Play Books, Kobo, Thorium, many others | Almost any app or browser | Any text editor or reading app | Any browser |
| E-ink readers | Kobo, PocketBook, Nook, Tolino open it directly; Kindle through Send to Kindle | Opens on most, usually awkward on small screens | Opens on most | Needs a connection or a saved copy |
| Screen readers and text-to-speech | Good, and the format has its own accessibility specification | Varies; scans without a text layer cannot be read aloud | Good | Good |
| Search and copy text | Yes | Only if the PDF has a text layer | Yes | Yes |
| Best for | Everyday reading on any screen | Printing, facsimiles, illustrated or typeset editions | Archiving, scripting, quoting, old devices | Trying a book before downloading |
Sizes above are typical ranges, not measurements of any particular file; a long illustrated EPUB and a short plain one can differ by an order of magnitude.
Which devices open which format
- Kindle e-readers and apps. Amazon’s Send to Kindle service accepts EPUB, PDF, TXT, HTML and several document formats, converts them, and delivers them to your library. Kindle devices do not open an EPUB file copied straight over USB; for that route, use the Kindle-format download Project Gutenberg provides. Details are in How to Read Free Ebooks on Kindle.
- Kobo, PocketBook, Tolino, Nook and most other e-ink readers. EPUB is their native format. Copying the file over USB or through the maker’s cloud is enough.
- iPhone and iPad. Apple Books opens EPUB and PDF from the share sheet or a download. TXT opens in Files, Notes or any text app.
- Android. Google Play Books, Moon+ Reader, ReadEra, Lithium and others open EPUB; most also handle PDF and TXT.
- Windows, macOS and Linux. Calibre (which also converts between formats), Thorium Reader and the built-in Apple Books on macOS handle EPUB. Browsers and PDF viewers handle PDF. Anything opens TXT.
Accessibility
EPUB is the format accessibility specialists recommend. The W3C publishes an EPUB Accessibility specification, and because an EPUB is structured HTML, screen readers can announce headings, move chapter by chapter and read the text aloud in order. Font, spacing, contrast and background can all be changed by the reader, which matters for low vision and dyslexia.
PDF accessibility depends on how the file was made. A typeset PDF with tags and a text layer can be read by a screen reader; a scanned PDF without optical character recognition is a set of photographs and cannot. If you rely on text-to-speech, prefer EPUB or TXT and avoid scans.
TXT is fully accessible in the sense that every tool can read it, but it carries no structure, so a screen reader cannot jump to the next chapter or tell a heading from a paragraph. For a short work such as The Raven this hardly matters. For Les Misérables it matters a great deal.
When TXT is the right choice
Plain text looks like the poor relation, but there are situations where it is the best download.
- You want to search or quote. Opening the TXT of Moby Dick in any editor and searching for a phrase is faster than paging through an EPUB.
- You are working with the text: building a concordance, running a word count, feeding a passage into a script, or preparing a reading for a class.
- Your device is old or restricted. A text file opens on hardware and software from any decade.
- Storage or bandwidth is tight. The text of a novel without images is usually the smallest file on offer.
- You want to make your own edition. Calibre and similar tools can turn a TXT file into an EPUB with chapter breaks of your choosing.
The trade-off is formatting. Poetry suffers most: line breaks survive in plain text, but indentation and spacing in a collection such as Leaves of Grass can come out uneven, and italics vanish entirely. Verse translations such as Samuel Butler’s prose Odyssey are less affected because they are set as paragraphs.
Reading online without any app
Every book on this site, and every book on Project Gutenberg, has an HTML version that opens in a browser. That is the quickest way to sample the first chapter of Jane Eyre before deciding whether to download it, and for many people it is the whole reading experience: a tablet browser with the font size turned up is a perfectly good e-reader. The drawbacks are that you need a connection unless you save the page, and that your place in the book is not remembered across devices the way a reading app would remember it.
A simple decision rule
- Reading on a phone, tablet or e-reader: download EPUB (or send it to your Kindle).
- Printing, or reading an illustrated or facsimile edition on a large screen: PDF.
- Searching, quoting, processing or using an old device: TXT.
- Just want to look: read online in the browser.
All of the formats hold the same words. If one does not suit your device, download another; public domain books have no copy limits. The legal background is covered in Public Domain Books Explained.
Frequently asked questions
Can I convert one format to another?
Yes. Calibre, a free desktop program, converts between EPUB, PDF, TXT, Kindle formats and many others. Converting EPUB or TXT to PDF works well; converting PDF to EPUB works poorly because the page layout has to be guessed back into paragraphs, and scanned PDFs cannot be converted at all without character recognition. Start from EPUB or TXT whenever you can.
Why does Project Gutenberg offer EPUB “with images” and “without images”?
Images are the bulk of an ebook’s file size. The version without them is smaller and loads faster on limited devices; the version with them keeps the illustrations and decorative plates from the original edition, such as the E. W. Kemble drawings in Adventures of Huckleberry Finn. If storage is not a concern, take the version with images.
Is MOBI still a format I should look for?
No. MOBI is an older Kindle format. Amazon stopped accepting it through Send to Kindle in 2022, and current Kindle downloads from Project Gutenberg use the newer Kindle format instead. If you already have MOBI files they will still open on older Kindles over USB, but there is no reason to seek the format out for new downloads.
Does PDF ever beat EPUB for ordinary novels?
Rarely. The cases are a large tablet or desktop monitor where the fixed page is comfortable, a facsimile of a historic edition where the original typesetting is the point, or printing. For everything else, the ability to reflow text wins.
