Compared, November 2026Book translator apps compared: 8 apps for EPUB and PDF on iPhone and Android

1Close Reader

Best for reading the original and translating what you need

Mine translates in place. Hold a word, and a card gives its meaning in that sentence, not a dictionary entry. “Whole sentence” and “Whole paragraph” translate more, or you select any passage. The book stays in its language, and you keep reading the original.

What it doesn’t do: translate a whole book or make a translated file. If that’s what you came for, Fablium and OpenNovel below do it. What it adds instead: “Who’s this?” for a forgotten name, explanations, chapter recaps and a chat about the book, all from the text only up to your page, and flashcards for the words you save. It opens EPUB, FB2, MOBI, AZW3, PDF and TXT on iPhone and Android. How it works, step by step.

2Book Translator: EPUB & PDF

Best low-cost tap-to-translate with offline packs

The closest to Close Reader on this list. Tap a word, a sentence or a paragraph, and it’s translated without leaving the page; since version 1.22 it can also translate the text automatically as you read. It opens EPUB, PDF, FB2 and TXT and lists 59 languages.

The free version has a daily limit, which the listing puts no number on, and the App Store listing says the app contains advertising. Premium, $2.99 a month or $24.99 a year, makes translation unlimited and adds offline translation with downloaded language packs. The listings don’t name the AI that translates. Translating a whole book isn’t there yet: in a Google Play reply of 9 May 2026 the developer called it an idea for a later update.

3Smart Book

Best for parallel text and your own AI key

A parallel-text reader: a paragraph’s translation appears under the original, for one paragraph on a tap or for every paragraph as you read. A tapped word or phrase is translated too. On the App Store it’s “SmartBook: Dual Language Books”; on Google Play, “Bilingual Books: Parallel Read”, with 30.4 thousand reviews.

It names its engines: Google Translate, DeepL, Reverso Context, ChatGPT, Claude, Gemini and Yandex, in about 100 languages, and it takes your own API key. A translation model can be downloaded for offline use. It opens EPUB, FB2 and TXT; PDF isn’t listed. On iPhone, paragraph translation, the choice of engines and AI translation are paid: $1.99 a month, $19.99 a year or $24.99 once. Both stores mark the app as containing ads.

4Readest

Best free and open-source option

An open-source reader for phones, desktops and the web. Select text and choose Translate, and a popup shows the translation beside the original. Its whole-book mode translates each paragraph as you scroll and puts the translation under the original: a bilingual page made as you read, not a translated file.

The built-in engines are DeepL, Azure, Google and Yandex. The free plan translates 10,000 characters a day, Plus ($4.99 a month) 100,000 and Pro ($9.99) 500,000. Your own DeepL key or any OpenAI-compatible service works on Plus, Pro or a one-time $19.99 purchase. Translation needs the network. Looked-up words go to a vocabulary list, with Anki export on the paid plans.

5Fablium

Best for a whole translated EPUB on iPhone

This one does what the search phrase says: it takes an EPUB and gives back a translated EPUB. You can preview one chapter before translating the whole book, choose a style (faithful, literary, modern or your own), keep a glossary of characters and terms, and edit single passages afterwards. The result is a Kindle-compatible EPUB.

It’s for iPhone only, takes EPUB only and translates into eight languages: Russian, Ukrainian, English, French, Spanish, German, Chinese and Arabic. You pay with one-off packs, $8.99 for Standard and $12.99 for Literary; how much text a pack covers isn’t on the listing. Its privacy policy names Anthropic as the translation provider, and the maker warns that AI makes mistakes and important passages should be reviewed. It came out in August 2026 and has no ratings yet.

6OpenNovel

Best for Chinese, Korean and Japanese web novels

Built for web novels in Chinese, Korean and Japanese. Paste a chapter’s link, and it fetches and translates the chapter, then the next one on request; it also takes an EPUB, pasted text or images. A glossary keeps names, pronouns and terms the same from chapter to chapter, and the site says a translated novel can be downloaded as an ePub.

It translates into English, Spanish, French, German, Arabic and, by its FAQ, 15 more languages. The free plan is 10 chapters a month; plans on the US App Store are $5.99, $11.49 and $22.49, and by its pricing page EPUB import starts with the middle one. Translating a tapped word isn’t listed: it’s for getting a translation, not for reading an original.

7Amazon Kindle

Best if your books are already in Kindle

In the Kindle app you highlight text, tap More, then Translation. Amazon calls it instant translations and lists it beside the dictionary, X-Ray and Wikipedia. It needs a connection. Amazon’s pages don’t say which languages it covers or what does the translating.

It works on a selection: I found no Amazon page about a reader translating a whole book. Kindle Translate, which you may have read about, is a tool for authors, an invite-only beta that translates their books between English and Spanish, German, French, Italian and Portuguese; readers then buy the translated edition. Your own files reach Kindle through Send to Kindle, and whether translation works in them I couldn’t confirm.

8Apple Books

Best free offline translation on iPhone

Nothing to install on an iPhone. Touch and hold a word in a book, adjust the selection and choose Translate. It’s the system translation that also works in Notes and Mail, and it can speak the text. With the languages downloaded it runs on the device, offline.

Apple lists 27 language entries for it, Arabic, Japanese, Russian and Ukrainian among them. It translates the selection and stops there: Apple’s pages list no translated file, word list or flashcards. And Apple Books has no Android app.