Book translation
Translate an entire EPUB with context carried across chapters, so terminology and tone hold from the first page to the last.
Translate books into eight languages, read bilingual editions, and turn your favourite books into natural AI audiobooks.
Original
It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness.
Translated ·
What DualBook does
One upload, four things: a translated book, a summary to judge it by, a bilingual edition to read it in, and an audiobook of either.
Translate an entire EPUB with context carried across chapters, so terminology and tone hold from the first page to the last.
A summary at three lengths — ultra brief, medium or detailed — so you can judge a book before committing to translating all of it.
Read the original and the translation side by side, aligned paragraph by paragraph, in a reader that keeps your place.
Turn the book — or just its summary — into natural narration you can listen to in either language.
Built on
Context-aware AI models
Whole-book translation, summaries, and text-to-speech
Google Sign-In
OAuth 2.0 account creation and authentication
Stripe
Payments on the web; App Store and Google Play in the apps
The problem
Most books are never translated into most languages, and a general translation tool handles a paragraph well but loses the thread across a whole book.
A general translation tool
Handles a paragraph well, falls apart over 300 pages
DualBook
Treats the whole book as one unit of work
Why choose DualBook
Nine capabilities, one system — book translation, summaries, bilingual reading and audiobooks all from the same upload. Hover a row to preview, click through for the detail.
Flexible output
One translation run produces both. Read the original beside the translation, or read the translation on its own like an ordinary book.
Original
It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness.
Translated
Đó là thời kỳ tốt đẹp nhất, cũng là thời kỳ tồi tệ nhất, là thời đại của sự khôn ngoan, cũng là thời đại của sự ngu xuẩn.
Read original and translated text together for maximum comprehension and language learning.
Translated
Đó là thời kỳ tốt đẹp nhất, cũng là thời kỳ tồi tệ nhất, là thời đại của sự khôn ngoan, cũng là thời đại của sự ngu xuẩn.
Đó là thời đại của niềm tin, cũng là thời đại của sự hoài nghi, là mùa của Ánh sáng, cũng là mùa của Bóng tối.
Get a clean translated version without the original text, just like reading a regular book.
Both formats generated from a single translation run — no extra cost
How it works
Drag and drop your EPUB file to get started
Choose the target language, the output format, and the translation style
Our AI processes and translates your book with precision
Most books finish in 10–30 minutes
Read your bilingual book with original and translation side by side
It was the best of times, it was the worst of times.
Đó là thời kỳ tốt đẹp nhất, cũng là thời kỳ tồi tệ nhất.
The free plan reads the first 20% of any book — no card required.
Start freePowerful reading tools
Look a word up, hear it pronounced, highlight a passage or listen to the chapter — without leaving the page you are reading.
Turn a translated book into an audiobook with 4 natural-sounding AI voices. Export as MP3 or M4B.
Look up any word instantly while reading. Get AI-powered definitions, IPA pronunciation with audio, and example sentences.
Select any text while reading for immediate translation. Adjust tone and style to match your needs (formal, casual, literary).
Highlight important passages with colours, add personal notes, and save bookmarks. Everything is stored with your account.
Highlights, notes, bookmarks, and reading position are stored with your account, so you can switch computers or browsers and pick up exactly where you stopped.
4 natural AI voices
Every word, one click away
Lack of good sense or judgement — sự ngu xuẩn.
Select, translate, choose a tone
It was the season of Light, it was the season of Darkness.
Là mùa của Ánh sáng, cũng là mùa của Bóng tối.
Mark it, note it, find it later
It was the epoch of belief, it was the epoch of incredulity, it was the season of Light.
Note — the two clauses mirror each other; keep the parallel structure in the translation.
Stop on the laptop, resume on the phone
Highlights, notes, bookmarks and position all travel with the account.
Inside the app
Screens from the product running today — upload, translation, the bilingual reader, dictionary lookups, summaries, audiobooks and your allowance.
Everything you have uploaded, with its translation state at a glance.
Drag and drop the file; the book is parsed chapter by chapter.
Choose the target language, the output style, and the AI model for the run.
Translation runs in the background; progress is tracked live per chapter.
Original and translation aligned paragraph by paragraph.
Definitions, IPA pronunciation and examples without leaving the page.
Ultra brief, medium or detailed — before committing to a full translation.
Four natural voices, exported as MP3 or M4B, chapter by chapter.
Hours of book, summaries and listens — the allowance, not a balance.
Security & privacy
One third party ever sees the text of a book you upload, and only to produce what you asked for.
Uploaded books and translations are stored with encryption and are visible only to your account.
Book text goes to a single AI provider to be translated, and nowhere else. Never sold, never used for advertising.
Remove a single book or your entire account from your settings whenever you want.
Bilingual reader
Keep the original beside the translation. Compare a sentence, check a phrase, and keep reading without switching apps.
Original
It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness.
It was the epoch of belief, it was the epoch of incredulity, it was the season of Light, it was the season of Darkness.
Translated
Đó là thời kỳ tốt đẹp nhất, cũng là thời kỳ tồi tệ nhất, là thời đại của sự khôn ngoan, cũng là thời đại của sự ngu xuẩn.
Đó là thời đại của niềm tin, cũng là thời đại của sự hoài nghi, là mùa của Ánh sáng, cũng là mùa của Bóng tối.
It was the best of times, it was the worst of times, it was the age of wisdom, it was the age of foolishness.
Đó là thời kỳ tốt đẹp nhất, cũng là thời kỳ tồi tệ nhất, là thời đại của sự khôn ngoan, cũng là thời đại của sự ngu xuẩn.
It was the epoch of belief, it was the epoch of incredulity, it was the season of Light, it was the season of Darkness.
Đó là thời đại của niềm tin, cũng là thời đại của sự hoài nghi, là mùa của Ánh sáng, cũng là mùa của Bóng tối.
Side by side — two columns. Stacked — read a paragraph, then its translation.
More about the bilingual readerAI audiobook
Listen to a book you translated, in the original language or the translation, narrated with natural AI voices — the whole book, or just its summary.
A whole-book narration is bought separately, priced by how long it runs — $2.99 to $16.99. Pro pays 20% less.
Create an audiobook More about AI audiobooksPricing Plans
Start free. Every plan is measured in what you actually do — hours of book, summaries, listens — so you know what you get before you pay.
Free Plan
$0
Free — no card required
Read the first fifth of any book, with one summary and one short listen a month.
Starter Plan
$4.99/month
Every month
About ten books a month, twenty summaries, and nine summary listens.
Pro Plan
Most popular$14.99/month
Every month
About thirty books a month, sixty summaries, thirty listens, and 20% off whole audiobooks.
Allowances reset every month. Upgrade, downgrade, or cancel at any time.
No plan includes a full narration: a whole book runs for hours, so it is priced by how long it runs. Pick the book after you buy — a purchase does not expire.
Pro pays 20% less at every length. Narrating a summary is already included in your plan — only whole-book narration is bought this way.
Plan Calculator
Pick a book length to see how far it goes on each plan, and what narrating it in full would cost.
How far it goes
Reading hours cover translating and reading. A book this long, every month:
Free Plan
Free
First 20% only
Starter Plan
$4.99/month
—
Pro Plan
$14.99/month
—
Narrating the whole book
—
Plans are measured in hours of book, not in characters. Create an account to start reading.
Reading in two languages
Read a real book in its original language with the translation beside it. Vocabulary and grammar stick better in a story you actually want to finish.
Read a paper or monograph with the original beside the translation, and look up unfamiliar technical terms without leaving the page. Highlights and notes stay attached to the passage.
Give students a side-by-side text so vocabulary and grammar are learned in context. Dictionary lookups include pronunciation audio for the words you want them to practise.
Read something you actually want to finish instead of a graded reader. When a sentence stops you, the translation is already next to it.
Get through a report or contract in a language you read slowly, with the original always available to check a phrase against.
Turn a book or a summary into audio and listen while commuting or exercising, then pick up the text where the audio left off.
Generate a short, medium, or detailed summary first, and commit to a full translation only once you know the book is worth it.
Blog
What we learn building a translation pipeline for whole books — and what actually helps people finish them.
How to Read a Book in a Language You're Still Learning
Tap-to-translate, pop-up dictionaries, whole-book translation, parallel text — four ways to read a foreign-language book with a safety net, and when each one starts working against you.
Read the post
How to Make a Bilingual Book: Three Methods Compared
Three ways to turn a book into a parallel-text edition: the open-source bilingual_book_maker, doing it by hand in...
How to Read English Books for Beginners
How to read English books for beginners: choose an easy story, follow the main action, check essential words,...
Easy Books to Read in English for Beginners
Seven accessible English books for beginner and intermediate learners, compared by language, structure, level, themes, and likely reading...
FAQ
Book translation, summaries, bilingual reading and audiobooks — answered
Still have questions?
Contact SupportAn AI book translator works on a whole book rather than a paragraph. It translates each chapter with the surrounding chapters in view, so names, terminology and tone stay consistent from the first page to the last. DualBook does that for EPUB files and hands the result back as an EPUB you can read, with the original beside it if you want. More on the AI book translator.
Yes. You upload the EPUB and the whole book is translated chapter by chapter, with context carried across chapters. Most books finish in 10–30 minutes and you can watch progress live from your dashboard. The free plan translates and reads the first 20% of any book, so you can judge the quality before paying.
EPUB is the format DualBook works with. Upload an EPUB and you get an EPUB back — bilingual or translation-only, both produced from the same run. Audio comes out as MP3 or M4B. See the EPUB translator.
Yes, at three depths — ultra brief, medium or detailed — written from the book's own text rather than from other people's reviews. It is the cheapest way to find out whether a title earns a full translation. See book summaries.
English, Vietnamese, Spanish, French, German, Chinese, Japanese and Korean — eight languages, in any direction. We add language pairs as we validate translation quality for them rather than listing ones we have not tested.
Yes — that is the bilingual reader. Original and translation are aligned paragraph by paragraph, either side by side or stacked, and you can switch between the two layouts mid-book. See the bilingual reader.
Yes. Any book you have translated can be narrated with four natural AI voices and exported as MP3 or M4B, chapter by chapter. You can also narrate just a summary if you want the gist rather than the whole book. See AI audiobooks.
We use large language models with context-aware chunking, so terminology and tone stay consistent across an entire book rather than drifting chapter to chapter. It is still machine translation: well suited to reading and studying, but we recommend reviewing anything you intend to publish or rely on professionally.
Your uploaded books and translations are stored with encryption and are visible only to your account. To produce a translation, book text is sent to a single AI provider for processing — that is the only third party that sees your content, and it is used solely to fulfil your request. We do not sell your data or use it for advertising. You can delete a book or your entire account at any time from your settings. Our processors are listed in full in the Privacy Policy.
Plans are measured in hours of book, not in characters or credits. The free plan reads the first 20% of any book with no card. Starter is $4.99 a month for 20 hours — roughly ten average-length books. Pro is $14.99 for 60 hours. Narrating a whole book is the one thing bought separately, from $2.99 to $16.99 depending on how long it runs.
Where we are
The full flow — account creation, EPUB upload, AI translation, bilingual reading, summaries, and audiobook generation — is live and usable today, with paid plans running through Stripe.
Try it with your own book
No card required. Upload an EPUB, choose a target language, and start reading in both.