How to translate a book (EPUB or PDF) on iPhone and Android

Close Reader is an e-book reader that translates while you read. Open your own EPUB, PDF, FB2 or MOBI file, hold a word, and its translation in that sentence appears over the page. One more tap translates the whole sentence or paragraph. The book itself stays in its language: Close Reader translates the parts you select and doesn’t make a translated copy of the file.

Translate a book in five steps

1. Install Close Reader. It’s free to download: App Store for iPhone and iPad, Google Play for Android phones and tablets. No account is needed.
2. Add your book. In the Library, tap +, then File on this device, and pick the EPUB or PDF. Or find the file in Files, Mail or a messenger and choose Close Reader under “Open in…”.
3. Check the language you translate into. Open Settings → Translate into and pick your language. The book itself can be in any language.
4. Hold a word. A card opens over the page with the word’s translation as it is used in that sentence, other meanings and a short note where one helps. A name gets “Who’s this?” first; the Translation tab is beside it.
5. Translate more when you need it. Under the translation, Whole sentence and Whole paragraph translate the sentence or paragraph around the word. To translate any other passage, drag the handles at the ends of the selection.

What a translated word gives you

A dictionary lists every meaning a word has. The card gives the one this sentence uses, then the others in a line, so the Spanish “sensible” comes out as “sensitive”, with a note that it’s a false friend. If the book is in your own language, the card gives a plain definition instead of a translation.

Save word keeps the word in your Vocabulary with its translation and the sentence you met it in. Flashcards then bring it back when it’s due.

EPUB, PDF and other formats

EPUB, FB2, MOBI, AZW3 and TXT books work the same way: the text fits your screen, and you hold a word or select a passage anywhere.

A PDF keeps its pages as they were laid out. Selection and translation work on it too, and two fingers zoom the page. The PDF has to contain real text. A scanned PDF is pictures of pages: there’s no text in it to select, and Close Reader doesn’t recognize text in pictures.

The file must be free of DRM. Books bought in the Kindle, Apple Books or Kobo stores are usually protected and open only in the store’s own app.

What Close Reader doesn’t do

• It doesn’t translate a whole book into a new file. There is no “translate this EPUB into Spanish” button. If you need a translated file, look at book translator apps compared: several of them do exactly that.
• It doesn’t translate offline. Reading needs no internet; translation does.
• It doesn’t open scanned PDFs as text or books protected with DRM.
• It isn’t available everywhere: the App Store and Google Play don’t offer it in some countries, Russia and China among them.
• A translation can be wrong. It’s made by AI. The flag under an answer reports it to us.

What it costs

The app is free to download, and reading, notes and flashcards are free. Translation is AI work and runs on energy (⚡). Your first 7 days come with 1,500 ⚡, with no account. Translating a word costs 1 ⚡; a sentence or a paragraph costs more, by its length.

After the first week, translation needs a plan or bought energy: plans start at $4.99 a month for 15,000 ⚡, and 10,000 ⚡ that never expire cost $2.99. These are US prices; your store shows yours. All plans are on the home page.

What is sent when you translate

To translate, the app sends the text you selected, with the sentences around it, to our server, which passes it to an AI provider. Nothing is sent before you allow AI features in the app. The Privacy Policy (section 3) lists what each feature sends and to whom.

Questions

Can Close Reader translate a whole book?

No. It translates what you select: a word, a sentence, a paragraph or a passage. It doesn’t translate the book from cover to cover and doesn’t make a translated file. If a translated file is what you need, see book translator apps compared.

Is it a free book translator?

Downloading the app and reading in it are free. Translation is AI work and runs on energy (⚡): your first 7 days come with 1,500 ⚡, and a word costs 1 ⚡. After that, translation needs a plan (from $4.99 a month) or bought energy.

Can I translate a PDF?

Yes, if the PDF has real text in it: you hold a word or select a passage as in an EPUB. A scanned PDF is pictures of pages, with no text to select, and Close Reader doesn’t recognize text in pictures.

Which languages does it translate?

The book can be in any language. You choose the language to translate into, from more than 40, in Settings → “Translate into”.

Does translation work offline?

No. Reading works without the internet; translation needs a connection.

Can I translate a book bought on Kindle or Apple Books?

Only if the file has no DRM. Books bought in those stores are usually protected and open only in the store’s own app. Close Reader opens your own EPUB, FB2, MOBI, AZW3, PDF and TXT files.

A book to try it on

If you’re learning English, start with a book whose words you mostly know: twelve free classics in English, ordered by how common their words are, each with an EPUB to download.