Last updated: 2026-10-12
To translate a Japanese light novel EPUB into English, upload the DRM-free EPUB file to EPUB Translator, choose English as the target language, and download the result. The English EPUB comes back laid out horizontally and paged left to right, with furigana removed from the translation and character names kept the same from chapter to chapter. A bilingual Japanese–English edition is included at the same price. There is no API key to set up: a 120,000-character light novel volume costs $3.99, paid once.
This guide is for one situation: a Japanese book you bought yourself, that has no official English translation, translated for your own reading. It is not a way to share translations. If an official English edition exists, buy that one.
The behaviour described below was tested on 2026-10-12 with vertical, furigana-annotated Japanese EPUBs built from public-domain Aozora Bunko texts, translated into English with the same pipeline and model settings that run in production.
Open EPUB Translator and drop the file in. The book is read in your own browser just far enough to show its title and cover back to you, and you do not need an account to get this far. You do not have to say the book is Japanese: the source language is detected from the text.
Pick English as the target language. Everything Japanese-specific below — the layout change, removing furigana, swapping the quotation marks — happens because the target is English. Translating the same book into Chinese or Japanese leaves its layout untouched.
Sign in, and the exact price for this file is shown before any payment step. It is worked out from the book's own character count. It is one payment for this book: no subscription, nothing to cancel.
Before translating anything, the whole book is read once to build a glossary (names and recurring terms with one fixed English rendering each) and a character list (the main characters, their gender, and how they address one another). Each passage is then translated with the entries that apply to it. Most books finish in minutes. You can close the tab; the job keeps running.
The cover, illustrations and table of contents stay in place, and the table of contents is translated too. Open either file in any EPUB reader.
Japanese light novels are typeset vertically (tategaki) and turn pages from
right to left. In an EPUB that is two settings: the stylesheet declares
writing-mode: vertical-rl, and the book's spine declares
page-progression-direction="rtl". A translator that only replaces the words
and copies everything else unchanged hands you English lying on its side,
with pages that turn the wrong way. That is exactly what our own output did
before 2026-10-12.
When the target language is written horizontally, the English EPUB is now rebuilt for it:
| In the Japanese EPUB | In the English EPUB |
|---|---|
writing-mode: vertical-rl in stylesheets and inline styles | horizontal-tb |
Spine page-progression-direction="rtl" | ltr — pages turn left to right |
Kindle primary-writing-mode set to vertical | horizontal-lr |
Furigana (<ruby> with <rt> readings) | Readings removed, the translated word kept |
| 「」 and 『』 | “ ” and ‘ ’ |
Language tag (dc:language, <html lang>) ja | en |
We checked the rendered result in the Chromium and WebKit engines: horizontal text, left-to-right paging. We have not yet tested inside the Apple Books app or the Calibre viewer specifically.
Furigana are the small kana readings printed beside kanji — in an EPUB they are
<ruby> markup with the reading in <rt>. Left alone after translation, they
end up in one of two broken shapes: the Japanese reading sitting above an
English name (Akechi Kogorō with あけちこごろう on top), or the English word
copied into its own reading, so it appears twice, one above the other.
So in the English EPUB the readings are removed and the translated text is kept. In the bilingual EPUB only the English side is cleaned: the Japanese paragraphs keep their furigana, which is what you want if you are using the book to read Japanese.
Light novels have big casts, nicknames, and dialogue that rarely says who is speaking. Translated one passage at a time, the same character can come out under three spellings, or switch gender between chapters. Two things work against that:
What that achieved in our test books: multi-character names and nicknames came out the same every time — 赤シャツ as Redshirt in all 168 occurrences, うらなり as Uranari in all 62, 明智 as Akechi in all 57. Every gender in the character list was right, and spot checks found no wrong pronouns.
Two rules specific to Japanese into English were added on 2026-10-12:
What is still not consistent, so you know before you buy:
You do not need an account with OpenAI, DeepL or anyone else, and there is no token bill to estimate. You pay us once for this book, and the price is shown before you pay.
Japanese light novel volumes uploaded to EPUB Translator run from roughly 90,000 to 170,000 characters. A 120,000-character volume, near the middle of that range, costs $3.99. The translation-only and bilingual EPUBs are both included. Current rates are on the pricing page.
Whatever tool you use, open the English EPUB and check two things: whether the text is still set vertically, and whether furigana are sitting above English words. Both come from the original file's styles and markup, not from the translation itself.
Upload the DRM-free EPUB to EPUB Translator, choose English, check the price shown for that book and pay once, then download. You get an English EPUB laid out horizontally with left-to-right page turns, plus a bilingual Japanese–English EPUB. No API key or software install is needed.
No. When the target language is English, vertical writing-mode settings are
changed to horizontal and the spine's right-to-left page progression is changed
to left-to-right, so the English reads like a normal English ebook. Translating
into Chinese or Japanese keeps the vertical layout.
In the English EPUB the furigana readings are removed and the translated words kept, so no kana sit above English text and no word is printed twice. In the bilingual EPUB the Japanese paragraphs keep their furigana.
Names are fixed in a glossary built from the whole book before translation, including one-character names and nicknames, and a character list keeps each character's gender and forms of address. Honorifics are kept as suffixes such as -san and -kun. In our tests names matched in nearly every occurrence, with rare slips. Each volume of a series is translated separately, so names can differ between volumes.
Yes. EPUB Translator is a web app: you upload the book and pay once for it. There is no AI provider account, no API key and no token bill. A 120,000-character light novel volume costs $3.99.
The price comes from the book's character count and is shown before you pay. Japanese light novel volumes uploaded to us run from about 90,000 to 170,000 characters; a 120,000-character volume costs $3.99. Both the English and the bilingual EPUB are included.
No. A DRM-protected file cannot be opened, so it cannot be translated. You need a DRM-free EPUB file.
Yes. Every translation also comes as a bilingual EPUB in which each Japanese paragraph is followed by its English translation, with the Japanese keeping its furigana. It is included in the same price.