DualBook 8 languages

Free online tool — no sign-up

Translate an English book into Portuguese

Upload an English EPUB and get the first fifteen pages back in Portuguese. Before a single sentence is written, the book has to commit to a variety — because Brazilian and European Portuguese disagree about more than accent.

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

The split here is wider than the one in Spanish. Brazilian Portuguese says está fazendo where European says está a fazer; the two use different pronouns for the same familiarity, place their object pronouns on opposite sides of the verb, and part company on ordinary nouns. A book that drifts between them does not read as regionally flexible — it reads as written by two people.

The second decision is the address one. English "you" says nothing; Portuguese has to choose, and in Brazil the everyday choice (você) is grammatically the formal one, which is exactly the kind of trap a paragraph-by-paragraph translator falls into repeatedly.

Both are settled by reading the whole book first. Names, recurring terms, register and who speaks to whom how go into a guide, and every page of the sample is translated against that guide instead of against the paragraph before it.

How it works

  1. Choose your English EPUB

    A DRM-free EPUB. The file stays on your device; only the text of the sample is sent.

  2. The model reads the whole book

    The variety, the register and the forms of address are fixed once, from the complete text.

  3. The first 15 pages come back in Portuguese

    About 4,500 words, translated as continuous prose so the rhythm survives.

  4. Download, or read it here

    A complete EPUB with the book's own styling. Accents, cedilla and til render everywhere.

What this free tool does not do

There is no variety switch. The free tool will not let you demand Brazilian or European Portuguese. What it guarantees is that it does not change its mind halfway through the sample.

Fifteen pages, not the book. About 4,500 words, counted in words.

Portuguese runs longer than English, commonly 20% or more, so the sample fills more screen than the English did.

The text is sent to a server and discarded when the job finishes.

Questions

Brazilian or European Portuguese?

Whichever the book's setting and register point to — there is no picker in the free tool. What is guaranteed is that the sample does not mix them: the variety, along with the vocabulary and the narrative voice, is settled from the whole book before any translating starts.

How is the form of address decided?

From the relationships mapped across the entire text. This matters more in Portuguese than in most pairs, because the pronoun people actually use in Brazil takes formal verb forms — so "informal" and "formal" are not where a word-by-word translator expects them.

Is it written with the current orthography?

Yes, post-1990 Agreement spelling, which is what current books in both Brazil and Portugal use.

How much is free?

About 4,500 words, roughly fifteen pages, five books a day per person.

Translate the whole book

The app runs the same engine across the entire book and can show the Portuguese next to the English, with your position synced between devices.

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