DualBook 8 languages

Free online tool — no sign-up

Make an English-Korean bilingual book

Each English paragraph with the Korean directly beneath it, in one EPUB. Read the English first; the safety net is on the page, not in a dictionary app.

The first 15 pages of text are sent to our server to be translated. The file itself stays on your device.

English and Korean put their words in nearly opposite orders, which is why a Korean learner can know every word in an English sentence and still not have the sentence. A dictionary does not fix that. A translation underneath does, instantly, and costs a glance instead of thirty seconds.

Your browser opens the EPUB, finds each paragraph and inserts the Korean beneath it, inside the original file. The chapters, table of contents and cover survive because only the chapter documents that receive translations are rewritten.

Stacked layout, which on a phone is the only one that works — and Korea reads on phones more than almost anywhere.

How it works

  1. Choose an English EPUB

    A DRM-free EPUB. The bilingual file is assembled in your browser, not on a server.

  2. The model reads the whole book

    Speech levels and name spellings are decided once from the whole book, so nothing shifts mid-chapter.

  3. Korean is inserted under each paragraph

    Each paragraph gets its translation styled beneath it, easy to tell apart at a glance.

  4. Read it here, or on your phone

    Hangul renders in essentially every reader, and the file keeps its own styling.

The trap, and the honest limits

Your eye will go to the Korean. Read the English first, every time. The moment of not-understanding is where the learning happens; skipping it means reading a translation with extra steps.

Fifteen pages get translations. The rest of the book stays in English in the same file.

The text is sent to a server and discarded when the job ends. The file never leaves your device.

Stacked, not columns — which is also what makes it usable on a phone.

Questions

Which side should I read first?

English first, every paragraph. Reading the Korean first means you can finish a whole book having practised almost nothing.

Will it open on a Kindle?

Yes. Kindle has accepted EPUB directly since 2022 — email it to your device or copy it across.

Do the cover and table of contents survive?

Yes. The browser rebuilds the archive entry by entry and only rewrites the chapter files that received a translation, so cover, navigation and metadata pass through untouched.

How is this different from a plain translation tool?

Same engine, different output. The translation tool replaces the English with Korean; this one keeps both — which for a word-order pair like this is the whole point, since you need to see how the sentence was rearranged.

The whole book, in parallel

The app builds the bilingual version of the entire book, with tap-to-look-up and pronunciation, and your position synced across devices.

Open DualBook