EPUB Translator (Translate E-books, with a Bilingual EPUB Option)

About the EPUB Translator (Translate E-books, with a Bilingual EPUB Option)

Open a DRM-free EPUB (EPUB 2 or 3) and get it back translated chapter by chapter — as a new EPUB in the language you choose, or as a bilingual EPUB in which every paragraph is followed by its translation. The copy keeps the book’s chapters, table of contents, styles, pictures, links and footnotes; only the words change.

Translate one chapter first to see the quality, protect names and terms with a short glossary, then translate the rest. Translation runs on your device: your browser’s built-in translator where it has the language pair (some desktop browsers have one), or an open translation model your browser downloads once from MySmartCoPilot — a small one for English ↔ Hindi and a larger one for many other pairs. Your book is never uploaded.

Every paragraph the translation may have got wrong is listed for review, and the copy says that it was machine-translated: it carries a short notice page and a note in its metadata, and it gets a new identifier so reading apps never mix it up with the original.

Common uses

• Reading a public-domain classic in your own language.
• Making a side-by-side bilingual edition for learning a language.
• Giving an author a first machine draft of their own book in another language, to hand to a human translator.
• Checking how a book you wrote reads in another language before you commission a translation.

What the translated copy contains

• The same book, in another language: every chapter in its place, the table of contents (navigation document or NCX) with translated titles, the original styles, fonts, pictures, links and footnote references, and the right language tags on the text (and right-to-left direction for languages such as Arabic or Urdu).
• A bilingual option: each paragraph is followed by a copy in the target language with the class “mt”, styled slightly lighter. Inside list items, table cells and poems the translation goes on its own line, so the structure stays valid.
• Honest labels: a notice page “Machine-translated on MySmartCoPilot with … — check before use”, a note in the package metadata, the target language as the book’s language, and a new identifier (the original’s is kept as the source). Obfuscated fonts are re-obfuscated for the new identifier, as the EPUB 3.3 specification requires.
• Nothing invented: passages the translation couldn’t handle stay in the original language, tagged as such, and are listed for you.

How the text is translated

Each paragraph, heading, list item, table cell and line of a poem is translated as one piece, a few sentences per request, so the translator always sees whole sentences. Emphasis, links and footnote marks inside a paragraph travel as numbered markers and are put back around the translated words; if a translator drops a marker, the paragraph keeps its translation in plain text and is listed as formatting simplified. Code, preformatted text, formulas, SVG drawings and anything marked “do not translate” are left exactly as they are. Text inside pictures is not translated.

Translators on your device

• Your browser’s built-in translator: some desktop browsers have one that handles many language pairs; the browser downloads its own language pack the first time. Phones don’t have it.
• A small model for English → Hindi and one for Hindi → English: about 115 MB each, downloaded once from MySmartCoPilot and kept for next time.
• A larger model for most other pairs among about 100 languages: about 615 MB. It is large for a phone; a computer is much faster.

The list under To groups the languages by what can translate them from your book’s language here. A pair nothing on this device can translate is not offered, and the page says what to try instead.

The review list

After each chapter, every paragraph that needs a second look is flagged: a translation much shorter or longer than the original, one that came back unchanged or in another language, a protected term that may be missing, simplified formatting, or a passage the platform’s safety check refused to send to the translator. Show only those paragraphs to read them side by side with the original, change your glossary if a name keeps going wrong, and translate the chapter again.

Before you rely on it

Machine translation can change meaning, miss idioms and get names wrong — check before you rely on it or share it. Translate only books you have the right to (your own writing, public-domain books, or for your own reading where the law allows), and don’t publish a translation of someone else’s book without permission. DRM-protected e-books aren’t supported.

Limitations

• DRM-protected books (Adobe, Readium LCP, Apple, Kindle) can’t be translated, and Kindle MOBI/AZW3 files must be converted to EPUB first.
• Up to 100 MB per book. The whole book stays in your browser’s memory while you work, so very large picture books may not fit on a phone.
• Machine translation is a draft: it can be wrong about meaning, tone, idioms and names, and poetry loses its rhyme and metre.
• A whole novel can take a long time with the downloadable models, especially on a phone; translate a chapter first to see how fast your device is.
• Fixed-layout books (picture books, comics) keep their positioned text boxes, so a longer translation may not fit its box. Text inside images is not translated.
• The translation lives only in this tab until you download it: closing or reloading the page loses it.

Privacy

Everything happens in your browser. What you enter or open here is not uploaded or stored by MySmartCoPilot. Translation runs on your device: your browser’s built-in translator where it has the language pair, or a translation model downloaded once from MySmartCoPilot (its size is shown before anything downloads). Your book is never uploaded.