Ebook Converter
You bought or downloaded a book and your e-reader refuses to open it — almost always because the file is in the wrong format. FluidConvert converts between EPUB, MOBI, PDF, AZW and other ebook formats instantly in your browser, free and with no account.
Drop your file here, or browse
Accepts: .epub, .mobi, .pdf, .azw, .azw3 · Max 1GB · always free
Your files are encrypted with TLS and automatically deleted after conversion.
Simply upload your .EBOOK file and we'll convert it to .EBOOK format — fast, free, and secure.
Fast & Free
Convert files up to 1GB completely free. No account, no limits.
Secure
Files are encrypted and automatically deleted after conversion.
High Quality
Industry-leading conversion with no quality loss.
How to Convert EBOOK to EBOOK
Upload Your File
Click the upload area above or drag and drop your .EBOOK file. We support files up to 1GB, completely free.
Choose Output Format
Select .EBOOK as your target format. Adjust any conversion settings if needed.
Download Your File
Click Convert Now and wait a few seconds. Once complete, download your converted file instantly.
About Ebook Converter
Why your e-reader rejects certain books
Ebook formats are tied to ecosystems. EPUB is the open standard supported by Apple Books, Kobo, Google Play Books, and most readers — but older Kindles historically didn't accept it. MOBI and AZW/AZW3 are Amazon's Kindle formats. PDF is universal but fixed-layout, so text doesn't reflow to fit smaller screens. When a book won't open, it's usually because you have an EPUB and a device that wants MOBI, or vice versa — converting bridges the gap.
Which format does your device need?
Convert to EPUB for Apple Books, Kobo, Nook, Google Play Books, and the broad majority of e-readers and reading apps. Convert to MOBI or AZW3 for older Kindle devices that don't accept EPUB. Convert to PDF when you want a fixed page layout for printing or reading on a large screen, accepting that text won't reflow on small devices. Matching the format to your specific reader is the whole game.
Reflowable vs. fixed layout
EPUB and MOBI are reflowable: the text rearranges to fit any screen size and font choice, which is why they're comfortable on phones and e-readers. PDF is fixed-layout: every page looks exactly as designed, ideal for textbooks, comics, and documents with precise formatting, but awkward on small screens because you often have to zoom and pan. Converting a PDF to EPUB makes it reflow, while converting an EPUB to PDF locks the layout — choose based on how and where you'll read.
How FluidConvert handles it
Ebooks convert in seconds on secure cloud servers, preserving chapters and text. Files are encrypted in transit and deleted automatically after conversion — your library stays private and is never stored.
Common reasons to convert EBOOK to EBOOK
- Converting an EPUB to MOBI so it opens on an older Kindle
- Turning a Kindle MOBI/AZW book into EPUB for Apple Books or Kobo
- Converting a PDF textbook to EPUB so the text reflows on a phone
- Saving an ebook as PDF for printing or fixed-layout reading
- Standardizing a mixed ebook library into EPUB for one reading app
Frequently Asked Questions
How do I get an EPUB onto my Kindle?
Older Kindles need MOBI or AZW3 rather than EPUB, so convert the EPUB to one of those formats first. (Newer Kindle software accepts EPUB via Send-to-Kindle, but converting guarantees it opens on any Kindle.)
What's the most widely supported ebook format?
EPUB. It's the open industry standard and works on Apple Books, Kobo, Nook, Google Play Books, and nearly every reading app — the safest choice for everything except older Kindles.
Should I convert my ebook to PDF?
Only if you want a fixed page layout for printing or reading on a large screen. PDF doesn't reflow text, so on phones and e-readers you'll have to zoom and pan. For comfortable small-screen reading, EPUB or MOBI are better.
Will converting keep the chapters and table of contents?
Converting between reflowable ebook formats (EPUB and MOBI) preserves chapters and navigation. Converting to or from PDF can change how navigation works, since PDF handles structure differently from dedicated ebook formats.
How large an ebook can I convert?
Up to 1GB per file, free and unlimited — far more than any text-based book, and enough for image-heavy ebooks and illustrated PDFs.