Free Online Ebook Converter
Reformat a book for any reader: EPUB, MOBI, AZW3, FB2, LIT or CBZ.
Up to 50 MB per file. Sign up free to convert files up to 100 MB.
| File name | Size | Convert to |
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Checking files and selected output formats.
About Ebook Converter
The ebook format landscape is more fragmented than any other file type. Amazon uses its own formats, Apple and Kobo prefer EPUB, PDF is still widely distributed as a book, and a dozen legacy formats remain in circulation. Converting without checking the destination reader usually produces a file the device will not open.
What follows covers each format, the readers that support it, and which parts of a book survive a conversion.
Format reference
| Format | Reflowable | Native reader | Best for |
|---|---|---|---|
| EPUB | Yes | Apple Books, Kobo, Google Play Books, Calibre | The open standard, first choice outside Kindle |
| AZW3 / MOBI | Yes | Kindle only | Sideloading to Kindle devices |
| No (fixed layout) | Every device | Technical books, cookbooks, comics | |
| FB2 | Yes | Cool Reader, Pocketbook, Calibre | Common in Eastern-European libraries |
| LIT / LRF / PDB | Yes | Legacy readers only | Older libraries |
Reflowable and fixed layouts
A reflowable ebook (EPUB, AZW3, MOBI, FB2) is HTML content that the reader app wraps to the page shape and font size the reader prefers. Increasing the text size re-flows the paragraphs rather than zooming the page.
A fixed-layout format (PDF, or fixed-layout EPUB) treats each page as an image. The arrangement is preserved exactly, which suits cookbooks, comics and children's books, but the text cannot reflow, so small screens require zooming. Converting a PDF novel to EPUB improves reading on a phone considerably; doing the same to an illustrated cookbook usually breaks it.
Which format to convert to
- For any non-Kindle device: EPUB, supported everywhere outside Amazon's ecosystem.
- For sideloading to a Kindle: AZW3. Amazon now accepts EPUB through Send to Kindle, but AZW3 gives finer control over formatting.
- For a book that must look identical everywhere: PDF, the only option that fixes the layout across readers.
- For reading a PDF on a phone: EPUB if the book is mostly text; keep the PDF if it carries complex layouts, illustrations or equations.
- For an archival copy of a legacy library: EPUB, the format most likely to still be supported in a decade.
What survives a conversion
Chapter structure, the table of contents, inline images, italics and bold, and paragraph breaks all carry over. Multi-column pages, sidebars, footnotes positioned beside their reference, custom fonts and drop caps generally do not.
For novels and most non-fiction the difference is unnoticeable. For textbooks, cookbooks and illustrated books it is not, so keep those as PDF when the arrangement on the page carries meaning.
DRM
Files downloaded from Kindle, Apple Books, Google Play Books or Kobo are usually DRM-protected, and that protection is enforced on the file itself. A converter cannot read the contents even when the format looks like ordinary EPUB or AZW3. Conversion requires a DRM-free copy, from sources such as Project Gutenberg, Standard Ebooks, Smashwords or an author's own site.
How to convert an ebook - step by step
Same flow for every ebook tool below, EPUB to MOBI, MOBI to EPUB, PDF to EPUB, and back.
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1
Pick the tool by source and target
Start with what you have. EPUB downloaded from Project Gutenberg? Old MOBI from an early Kindle purchase? PDF of a public-domain novel? Each dedicated tool page is tuned for that specific pair and handles the format quirks (chapter markers, cover art placement, metadata mapping) automatically.
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2
Upload your ebook
Most ebook files are small, a typical novel is 1-3 MB, well within the free-tier 100 MB cap. Illustrated books, textbooks, or scanned PDFs can be much larger; those need a Pro plan for anything over 100 MB. Batch conversions of up to 20 files are handy for cleaning up a legacy library in one pass.
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3
Let the defaults do their thing (usually)
Ebook conversions have far fewer knobs than image or video. The tool preserves structure and metadata by default. Where a setting matters, say, converting a scanned PDF where you'd rather keep the images than force text reflow, the tool page calls it out with a one-line explanation.
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4
Convert - download - and side-load
The output is ready in a few seconds. Download to your device, then move the file to your reader: Books.app on iPhone/iPad, Send-to-Kindle for Amazon devices, or drop it directly into Calibre for a full library workflow. Both the upload and the converted files are deleted within 1 hour.
Common mistakes
- DRM-protected files won't convert. If your ebook came from Kindle, Apple Books, Google Play Books, or Kobo, it's likely locked. Buy or find a DRM-free copy first, Standard Ebooks, Project Gutenberg, and most indie authors' sites offer them.
- PDF-to-EPUB is best-effort on scanned books. If the PDF is text-based (searchable), conversion works cleanly. If it's a scanned image PDF, the result is an EPUB full of images, technically valid, but a poor reading experience on a phone.
- Send to Kindle now accepts EPUB. Amazon updated the flow, you no longer need to convert EPUB to AZW3 unless you want fine control. EPUB via Send-to-Kindle just works.
- Preserve your source. Always keep a copy of the original file. If a conversion has an issue you notice weeks later, you can re-convert without hunting down the source again.