EPUB Viewer. Read EPUB Books Online, Privately
Drop an.epub and it opens into a real reader: paginated pages you turn like a book, a clickable table of contents, adjustable font size, and light, sepia or dark themes for comfortable reading. Keyboard arrows flip pages, your place is remembered as you go, and the whole book stays on your device, never uploaded.
What is the epub viewer?
The EPUB Viewer opens and reads any .epub book in your browser as a paginated, book-like reader. It includes a table-of-contents sidebar, adjustable font size and light, sepia or dark themes. Everything runs on your device, so the book is never uploaded and never leaves your machine. Free to use.
The GigAI EPUB Viewer turns any EPUB file into a comfortable, distraction-free reading experience without installing an app or handing your book to a website. Drop an.epub onto the page (or click to browse) and it opens instantly into a paginated rendition that reflows to fit your screen. You turn pages with the on-screen controls, your keyboard's arrow keys, or a tap on either side. A collapsible table-of-contents panel lists every chapter and section pulled straight from the book's own navigation, so one click jumps you anywhere in the text. Reading long-form? Bump the font size up or down until it's easy on your eyes, and switch between a clean light theme, a warm sepia page for evening reading, or a true dark theme that's kind on OLED screens at night. The book's title, author and cover metadata are shown up top so you always know what you're in, and your reading position is tracked as you move through the spine. Because everything runs on epubjs inside your browser, the entire archive (text, images, styles and fonts) is parsed and rendered in memory on your machine. The file is never uploaded, stored or logged, which makes it safe for review copies, unpublished manuscripts, personal libraries and anything you'd rather not send to a server. Two honest notes: EPUB is a reflowable format, so this is a faithful web rendition of the book's content, not a pixel-for-pixel reproduction of a specific print edition's page breaks: chapters, headings, emphasis, lists and inline images all render, but the exact typeset pagination of a paper book is re-flowed to your screen. And DRM-protected EPUBs (encrypted store purchases from some retailers) can't be opened by any in-browser reader, this one included. Use a DRM-free.epub. When you'd rather have a fixed, shareable file than an on-screen reader, the sibling EPUB to PDF tool linearises the same book into a downloadable PDF, and EPUB to Text extracts the raw prose.
- Difficulty:
- Easy
- Typical time:
- ~15s
- Processing:
- 100% browser processing
Last updated
How to use the epub viewer
- 1
Open your EPUB
Drop an .epub file onto the page or click to browse. The book is opened in memory and its title, author and table of contents appear right away.
- 2
Turn the pages
Use the on-screen previous / next controls, your keyboard's left and right arrow keys, or tap either side of the page to move through the book.
- 3
Navigate with the contents
Open the table-of-contents sidebar and click any chapter or section to jump straight there. Collapse the panel for a clean, full-width reading page.
- 4
Tune your reading comfort
Increase or decrease the font size and pick a light, sepia or dark theme until the page is easy on your eyes: changes apply instantly.
What EPUB Viewer includes
Paginated, book-like reading
Your EPUB reflows into real turn-the-page columns that fit the screen, flip forward and back with the on-screen controls, your keyboard's arrow keys, or a tap on either side, just like a dedicated e-reader.
Table-of-contents navigation
A collapsible sidebar lists every chapter and section straight from the book's own navigation. Click any entry to jump there instantly. The panel tucks away when you want a clean, full-width page.
Adjustable font size
Scale the type up or down to whatever's comfortable, the page reflows around your choice, so long reading sessions stay easy on the eyes without squinting or zooming the whole browser.
Light, sepia & dark themes
Read on a crisp light page by day, a warm sepia sheet in the evening, or a true dark theme that's gentle on OLED screens at night: switch instantly without reloading the book.
Metadata & reading position
The book's title, author and details are shown up top so you always know what you're reading, and your place is tracked as you move through the spine while the tab stays open.
100% private, in-browser
The entire archive is opened and rendered locally with epubjs. Review copies, drafts and personal libraries are never uploaded, stored or logged: close the tab and nothing remains.
Why use our epub viewer
Read an EPUB without installing anything
No Calibre, no Kindle app, no browser extension. Drop the file and read, perfect for a locked-down work laptop, a borrowed machine, or a quick look at a book someone just sent you.
Your book never leaves your device
Unlike upload-based readers, nothing is sent to a server. Unpublished manuscripts, ARC review copies and private notes stay entirely on your machine, which matters when the content is confidential.
Comfortable for long-form reading
Adjustable type size and warm sepia or true-dark themes make a full chapter pleasant to read on screen, not just skimmable. This is a reader, not a raw file dump.
Jump anywhere in one click
The real table of contents means you never scroll blindly. Land in the exact chapter or section you want, then flip pages naturally from there.
Built for the way you work
From quick one-off fixes to daily workflows, see how people put this tool to use.
- Reader / Book lover
Read a DRM-free ebook anywhere
Open a public-domain classic, an itch.io or Standard Ebooks download, or a book a friend shared, and read it comfortably without buying into one store's app ecosystem.
- Author / Editor
Proof a manuscript privately
Check how an exported.epub actually renders (chapter breaks, headings, images) before publishing, with the confidence that the draft never touches a third-party server.
- Reviewer / Blogger
Read an ARC review copy
Open an advance review copy in the browser to read and reference on any machine, keeping the embargoed file on your own device instead of an upload service.
- Student / Researcher
Read course texts on any device
Open an assigned .epub on a lab or library computer with nothing to install, bump the font up, and switch to a dark theme for late-night sessions.
Supported formats
Accepts EPUB, and produces On-screen reading view, all processed locally in your browser.
- EPUB
- On-screen reading view
Frequently asked questions
Recommended tools
EPUB to PDF
Convert an EPUB ebook to a clean, printable PDF in your browser. Chapters are read in order and paginated to A4 or US Letter, text, headings and images intact. Nothing is uploaded, and it's honest about reflow.
Document Comparer
Compare two documents and see exactly what changed. Upload two PDF, Word, RTF, text or Markdown files and get a color-coded diff (additions in green, removals in red) with an added/removed count, all in your browser. Nothing is uploaded.
Document Viewer
Open and view almost any document in your browser. Drop a PDF, CSV, Excel, text, Markdown, EPUB, RTF or image file and the viewer auto-detects the format and previews it instantly, paged PDFs, scrollable spreadsheets, rendered Markdown and more. Nothing is uploaded.
RTF Viewer
Open and read.rtf (Rich Text Format) files right in your browser. Drop or paste an RTF document and see its formatted text (bold, italic, underline and paragraphs) then export clean HTML or plain text. Nothing is uploaded.
CSV Editor
Open, edit and clean CSV files in your browser as a real spreadsheet, fix cells, add or delete rows and columns, sort, find, and export to CSV, JSON or Excel. Nothing is uploaded.
CSV to Excel
Convert CSV to a real Excel.xlsx file in your browser. Paste or drop a.csv, preview the parsed grid live, name the sheet, and download a workbook that opens natively in Excel, Google Sheets and LibreOffice. Delimiter is auto-detected. Nothing is uploaded.
Common problems, solved
Hit a snag? Here are quick fixes for the issues people run into most.
My EPUB won't open. It says it can't be read.
The most common cause is DRM: encrypted purchases from some stores can't be opened by any in-browser reader. Confirm the file is a DRM-free .epub. Also make sure the file is a real EPUB (a ZIP archive) and not a renamed .mobi/.azw or a corrupted download.
The pages don't match my paperback's page numbers.
EPUB is a reflowable format, so pagination depends on your screen size and font settings rather than a fixed print edition. That's expected: the content, chapters and order are faithful, but exact page breaks are re-flowed to your device, not reproduced from a specific paper edition.
Some images or fancy layout look plain.
Standard inline images, headings, emphasis and lists render. Very complex fixed-layout EPUBs (heavily designed cookbooks, comics, textbooks) rely on precise CSS that a reflowable reader simplifies. For those, the sibling EPUB to PDF export may better preserve a continuous reading flow.
The table of contents is empty or thin.
The sidebar is built from the book's own embedded navigation. Some older or hand-made EPUBs ship an incomplete or missing table of contents. You can still read the whole book by turning pages, even when the chapter list is sparse.
Get the most out of it
Use your keyboard's left and right arrow keys to turn pages hands-free while you read.
Switch to the sepia theme for evening reading and the dark theme at night. Both are easier on the eyes than stark white.
Bump the font size up a notch or two on a large screen. The page reflows so nothing gets cut off.
Collapse the table-of-contents sidebar for a wider, distraction-free page, and reopen it only when you need to jump.
Only DRM-free.epub files open in any browser reader, if a store book won't load, that's the reason.
What's new
Recent updates and improvements to the epub viewer.
Initial release, in-browser EPUB reader with paginated page turns, a table-of-contents sidebar, adjustable font size, light/sepia/dark themes and book metadata, powered entirely by epubjs on-device.
Added keyboard arrow-key page navigation, a true dark reading theme tuned for OLED screens, and a clearer honesty note about DRM and reflowable pagination.
Improved table-of-contents jump accuracy for nested sections and reduced initial render time for large books.
Keep exploring
Problems we solve
Definitions
From the blog
- The EPUB Format Explained: What It Is, How to Read It, and How to Convert It
- Best Free Online Image Tools in 2026 (No Sign-Up, No Watermark)
- How to Convert Markdown to PDF: Turn Plain Text Into a Polished Document
- How to Convert Excel to PDF: Keep Your Spreadsheet Readable When You Share It
- What Is an SVG and Why Use It? Vector vs Raster, Explained
Explore categories
By file type
Common tasks
Your privacy is built in
Your EPUB is opened, parsed and rendered entirely in your browser with epubjs. It is never uploaded to any server. Nothing is stored, logged or transmitted, so you can safely read review copies, unpublished manuscripts and private books. The whole archive, including its text, images and fonts, stays in memory on your device. Close the tab and every trace is gone.
- Runs in your browser
- No uploads
- Nothing stored
Ready to try the epub viewer?
Free, private and instant. EPUB Viewer runs right in your browser.