ClickBook
English
ClickBook app icon

Tap any word.
Read anything.

ClickBook is an offline EPUB and readable-PDF reader with on-device AI. Tap a word you don't know and get an instant meaning, translation and example sentence in your mother tongue — no account, no cloud AI, no ads.

See what's inside How your data stays private
  • Runs on your device
  • 40+ languages
  • No account
  • No ads or trackers

Available now on Android, iPhone and iPad.

Features

A reader that explains itself

Everything you need to read in a second language, without leaving the page or handing your library to anyone.

Tap-to-explain

One tap on any word gives you a meaning, a translation and an example sentence — written on your phone, in seconds, using the sentence around it as context.

Offline by design

Once the model is in place, reading and lookups need no connection. Network use is limited to purchases, restores, entitlement checks and optional backups.

A reader worth staying in

Serif typography, justified text, sepia and dark page colours, adjustable size and line height, and paged or scrolling modes. Built for long sessions.

Your mother tongue

Pick the language you actually think in. Explanations and translations come back in that language every time, whatever the book is written in.

Your library, your files

Import EPUB files and readable PDFs from your device. ClickBook keeps your position, settings and saved words in a local library you control.

No accounts, no tracking

No sign-up, no advertising SDKs, no third-party analytics. The words you look up are nobody's business but yours.

In the app

This is what tapping a word looks like

  • The ClickBook library showing three books with covers and reading progress.

    Your own EPUB files, with three classics already on the shelf.

  • A page of Little Women with the word dreadful tapped, and a panel explaining that it means something very unpleasant, with example sentences.

    Tap a word and it is explained where you are reading, without leaving the page.

  • The same word open on the Translation tab, explained in German.

    Answers come back in your mother tongue, whatever the book is written in.

  • The Context tab showing the whole sentence around the word rendered in German.

    Context takes the sentence you are stuck on, not just the word.

  • A list of languages with German selected as the language for word translations.

    Choose your mother tongue once during setup, from more than forty.

  • A settings panel listing Meaning, Example, Translation and Context with arrows to reorder them.

    Decide which answer the AI writes first, and which it skips.

  • Reader settings showing serif, sans, condensed and monospace typefaces with a size control.

    Four typefaces and a size that goes as large as you need.

  • Reader settings showing page colours and compact, standard and large line spacing.

    Paper, sepia, mint or dark, with line spacing to match your eyes.

  • Reader settings with fullscreen enabled and page by page chosen over continuous scroll.

    Turn pages or scroll, and hide everything but the book.

How it works

Three steps, then you're reading

  1. One-time setup

    On first launch ClickBook prepares its on-device AI model and asks for your mother tongue. On iOS the model already ships with the app; on Android it downloads once.

  2. Import your book

    Pick an EPUB or readable PDF from your phone. ClickBook copies it into its local library, prepares the reader files it needs, and remembers where you stopped.

  3. Tap any word

    Hit a word you don't know. ClickBook reads the surrounding sentence and writes an explanation, a translation and an example — locally, in your language.

Built for reading, not for tracking.

ClickBook has no user accounts, no advertising SDKs and no third-party analytics. The text you read, the words you tap and the explanations generated for them are processed on your device — they are not sent to our servers for cloud AI processing.

Network access is limited to operational things: app-store purchase and restore flows, purchase entitlement checks, platform services, optional backups, and — on Android — the one-time AI model download. Read the full Privacy Policy.

Languages

Read in one language, think in another

Choose your mother tongue once and every explanation arrives in it. More than 40 languages are available, including:

FAQ

Common questions

Does ClickBook work offline?

Yes. Once the on-device AI model is in place, reading and word lookups run entirely on your phone with no internet connection. Network access is only used for things like app-store purchases and restores, entitlement checks, platform services and optional backups.

Is the text I read sent to a server?

No. The book text you read, the words you tap and the explanations generated for them are processed on your device. ClickBook does not send them to our servers for cloud AI processing.

Which file formats can I import?

EPUB files and readable PDFs. A readable PDF is one that contains real text — scanned, image-only PDFs cannot be read, because there is no text layer to extract.

Do I need an account?

No. ClickBook has no user accounts and no sign-up. Your library, reading positions and settings live on your device.

How large is the AI model?

The model is ClickBook Gemma 4 E2B multi (IQ4_XS) in GGUF format, roughly 1.84 GB. On iOS it ships inside the app, so there is nothing to download. On Android it is delivered by Google Play during first-run setup — best done on Wi-Fi.

What is ClickBook Pro?

An optional purchase that unlocks extra capability such as deeper AI reasoning for a more careful answer. The reader itself works without it. Purchases are handled by the App Store or Google Play, and a purchase on one platform does not carry over to the other.

Which languages are supported?

More than 40 mother-tongue languages, including English, Spanish, French, German, Italian, Portuguese, Dutch, Polish, Russian, Ukrainian, Turkish, Arabic, Hebrew, Persian, Hindi, Bengali, Thai, Vietnamese, Indonesian, Chinese, Japanese and Korean.

Does it need a fast phone?

The AI runs locally, so a recent device gives noticeably quicker explanations. ClickBook is built for phones from roughly 2021 onwards; older or lower-memory devices may respond more slowly.

Where can I get ClickBook?

ClickBook is available now on Google Play for Android and on the App Store for iPhone and iPad.

Articles

More on reading in another language

Practical writing on the things this app exists to solve.

All articles · Free books to read while you learn

Help & Legal

Everything else

Support & FAQ

Setup, the model, purchases, imports, and how to reach a human.

Privacy Policy

What stays on your device, the limited network use, purchases, and your rights.

Terms of Use

Your licence, responsibilities for imported files, Pro purchases and consumer information.

Impressum

Provider identity and contact details, as required under German law.