DualBook 8 languages

Free online tool — no sign-up

Translate an English book into Persian

Upload an English EPUB and get the first fifteen pages back in Persian. Persian has an invisible character that decides whether a word is one word or two, and most text pipelines quietly delete it.

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

The zero-width non-joiner — the half-space — is what separates می‌رود from میرود and keeps a plural ending from fusing into the noun in front of it. It has no width, so stripping it does not look like damage; it looks like slightly wrong spelling, everywhere, in a way an editor would catch and a machine would not. The text produced here carries it through as an ordinary character of the translation, because that is what it is.

The register decision is the other half. Written Persian narration and spoken Tehrani are noticeably different languages, and modern novels use both — narration in the literary form, dialogue closer to speech. Which side a book sits on has to be decided once and held, not renegotiated per chapter.

So the model reads the whole book before translating: names, recurring terms, tone and who is addressed as شما rather than تو go into a guide, and the sample is written against 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

    Names, register and the شما/تو map are settled once, from the complete text.

  3. The first 15 pages come back in Persian

    About 4,500 words, with the half-space preserved wherever the Persian needs it.

  4. Download, or read it here

    A complete EPUB with dir="rtl" written onto the translated text, so it aligns and punctuates correctly.

What this free tool does not do

Gender disappears, and that is Persian, not a defect. Persian has one third-person pronoun for he and for she. An English "he said" and "she said" become the same word, and the reader works it out from the names — exactly as a Persian novel does.

Formality is inferred. The English never marked it; the guide makes the inference consistent across the sample rather than authoritative.

Fifteen pages, not the book, and the text is sent to a server and discarded when the job ends.

Questions

Does the Persian read right-to-left in the file?

Yes. The translated text carries an explicit direction attribute and a Persian language tag, so a reader aligns it to the right edge and places the punctuation correctly, including in sentences that also contain Latin words or numbers.

Is the half-space preserved?

Yes. The zero-width non-joiner is part of the text and is carried through the file like any other character. It is the detail most conversion pipelines lose, and losing it makes every affected word subtly misspelled.

Literary Persian or colloquial?

It follows the book. Narration usually lands in the written register and dialogue closer to speech, which is how contemporary Persian novels are written — and the choice is made once for the whole sample rather than drifting.

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 Persian next to the English, with your position synced between devices.

Open DualBook