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Free Online Ebook Converter

Convert between ebook formats online for free. Supports EPUB, MOBI, AZW3, FB2, LIT, PDB, CBR, CBZ and more. Fast, secure, browser-based conversion with no software to install.

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Ebook conversion is a category most people run into once, get confused by, and then avoid — because the ebook format landscape is more fragmented than any other file type. Between Amazon's proprietary formats, Apple's preference for EPUB, the resurgence of PDF-as-book, and a dozen legacy formats still floating around, the "just convert it" instinct often lands you with a file your device politely refuses to open.

This overview covers what each ebook format actually is, which reader supports what, and how to convert without losing the parts of a book that matter — chapter structure, table of contents, embedded images, and readable typography.

The five formats that actually matter in 2026

Formato Reflowable Native reader Melhor para
EPUBSimApple Books, Kobo, Google Play Books, CalibreThe open standard — first choice for non-Kindle
AZW3 / MOBISimKindle onlySideload para dispositivos Kindle
PDFNo (fixed layout)Every deviceFixed layouts — technical books, cookbooks, comics
FB2SimCool Reader, Pocketbook, CalibreCommon in Eastern-European libraries
LIT/LRF/PDBSimLegacy readers onlyOnly if you inherited an older library

Reflowable vs. fixed — the single biggest choice

A reflowable ebook (EPUB, AZW3, MOBI, FB2) is essentially a small website: HTML content that a reader wraps into whatever page shape and font size the user prefers. Turning up the text size doesn't zoom in — it re-flows the paragraphs. That's the reading experience most people expect from an ebook.

A fixed-layout format (PDF, or fixed-layout EPUB) treats every page as an image. Layout is preserved exactly — good for cookbooks, comics, and children's books — but text doesn't reflow, so on a small screen you're pinching to zoom. Converting a PDF novel into an EPUB usually improves the reading experience dramatically; converting an illustrated cookbook the same way often breaks the layout.

Choosing a target — a short decision tree

  • Reading on any non-Kindle device? Converter para EPUB. It's the industry standard and works everywhere except Amazon's ecosystem.
  • Sideloading to a Kindle? Converter para AZW3. Amazon accepts EPUB via "Send to Kindle" now, but AZW3 gives you finer control over formatting.
  • Sharing a book that must look identical on every device? Converter para PDF. Nothing else guarantees pixel-exact layout across readers.
  • Digitising a PDF for reading on a phone? Converter para EPUB if it's mostly text. Keep the PDF if it's mostly images, complex layouts, or contains equations.
  • Cleaning up a legacy library? Convert everything to EPUB as your archival master. It's the only ebook format with a real future.

What survives (and what doesn't) in an ebook conversion

A well-executed ebook conversion preserves chapter structure, table of contents, inline images, italics and bold, and paragraph breaks. It rarely preserves complex layouts (multi-column pages, sidebars, footnotes on the same page as the reference), custom fonts, or drop caps and other typographic flourishes.

For most novels and non-fiction, this trade-off is invisible. For textbooks, cookbooks, and illustrated books, the layout loss is real. If a book relies heavily on how it's arranged on the page, keep it as PDF.

DRM — the reason "just convert it" sometimes fails

Um arquivo baixado do Kindle, Apple Books, Google Play Books ou Kobo provavelmente está protegido por DRM. Essa proteção é aplicada no nível do arquivo: mesmo que o formato se pareça com EPUB ou AZW3, um conversor não conseguirá ler o conteúdo. Se sua fonte veio de uma loja comercial, você precisará comprar e baixar o livro de uma fonte sem DRM (Project Gutenberg, Standard Ebooks, Smashwords, a maioria dos sites de autores independentes) antes que a conversão seja possível.

What every iFormat ebook converter does the same way

All the tools listed below process ebooks on isolated per-request workers, with TLS-encrypted uploads and 30-minute auto-delete on both source and output. Table of contents, chapter breaks, and inline images are preserved by default across supported format pairs. Metadata (title, author, publisher, cover art) carries through wherever the target format supports it.

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.

  1. 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.

  2. 2

    Upload your ebook

    Most ebook files are small — a typical novel is 1-3 MB, well within the free-tier 10 MB cap. Illustrated books, textbooks, or scanned PDFs can be much larger; those need a Pro plan for anything over 10 MB. Batch conversions of up to 20 files are handy for cleaning up a legacy library in one pass.

  3. 3

    Deixe os padrões fazerem o que querem (normalmente)

    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.

  4. 4

    Converter, baixar e carregar lateralmente

    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 30 minutes.

Tips people usually learn the hard way

  • Arquivos protegidos por DRM não serão convertidos. 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. Mantenha sempre uma cópia do arquivo original. Se uma conversão apresentar um problema que você perceber semanas depois, você poderá reconverter sem procurar a fonte novamente.

When you actually need to convert an ebook

Six honest scenarios where the format swap is the whole job.

Moving a library between reader ecosystems

Bought a Kobo after years of Kindle? Switching from Amazon to Apple Books? Your existing MOBI or AZW3 collection needs to become EPUB (or PDF) to work outside Amazon's ecosystem. Converting the whole library in one batch is a common one-time job when someone changes devices.

Ler um romance em PDF em um telefone sem apertar para aplicar zoom

A PDF-formatted book on a phone screen is a rough experience — text is too small to read at native zoom, and swiping between pages feels clunky. Converting to EPUB reflows the text to fit the screen, making the same book actually readable. Works well for text-heavy content; less well for anything layout-driven.

Sideloading a public-domain book to your Kindle

Project Gutenberg offers most books as EPUB. Getting them onto a Kindle used to require converting to AZW3 first, but Amazon's Send-to-Kindle now handles EPUB directly. Convert to AZW3 only if you want tight control over the formatting on the Kindle.

Consolidating a legacy library to one format

If you've been collecting ebooks for a decade, chances are the library is a mess: LIT files from an old reader, FB2 from a Russian archive, MOBI from an early Kindle, EPUB from newer sources. Converting everything to EPUB (the only ebook format with real 2026-onward support) gives you one archival master that every reader on the market can open.

Preparing your own writing for readers

Writers and self-publishers often work in Word or Google Docs, then need to convert to EPUB for distribution and AZW3 for Kindle Direct Publishing. Converting from DOCX to EPUB (with a quick clean-up pass in the reader) is usually the fastest path from manuscript to shippable ebook.

Making a textbook portable across devices

Academic PDFs are usually fine at a laptop or tablet size, but painful on phones. Converting to EPUB works well when the textbook is mostly prose; keep the PDF if the book leans heavily on tables, equations, or diagrams that would break on reflow. Some students keep both — EPUB for reading, PDF for reference.

Not sure which conversion fits your case? Skim the grid below — each entry is labelled with source and target format and includes a note on what to expect from the result.