Decipher
Read real books in any language with live translation. Powered by 70,000+ free books from Project Gutenberg.
The Problem
Language apps teach you to swipe. Not to read.
You've kept a 200-day streak on a language app. You've earned every badge. But you still can't read a menu, a news article, or a book in your target language without panicking.
That's because the most effective way to learn a language isn't flashcards or gamified drills — it's reading. Real reading. Linguists have known this for decades. The problem was never the method — it was the friction. Switching between a book, a dictionary, and a notes app just to get through a page.
Decipher removes that friction entirely.
Our biggest update since launch.
Faster browsing, curated books for learners, and Premium is finally here. If you've been waiting on a reason to come back to Decipher, this is it.
Curated for Learners
44 hand-picked books across 7 languages, tagged 1–5 by difficulty. Pick something that'll actually move the needle.
Premium upgrade is live
$6.99 one-time purchase removes all daily limits forever. No subscription, no recurring charges.
Sort by Popular, Newest, or Oldest
Find what you're looking for faster across the full Gutenberg library.
In-app bug reports & feedback
Found a bug? Got an idea? Settings → Support sends it straight to me. No more bouncing out to your email client.
Features
Everything you need to read in another language. Nothing you don't.
Tap-to-Translate
Tap any word for an instant translation without leaving the page. See alternate meanings, and keep reading without breaking your flow.
70,000+ Free Books
Browse Project Gutenberg's entire library. Real literature — the same books native speakers grew up with. Sort by Popular, Newest, or Oldest to find what you're after fast.
Curated for Learners
Don't want to start with Don Quijote? Pick from 44 hand-picked books across 7 languages, tagged 1–5 by difficulty. Each includes a short note on why it works for language learners.
Import Your Own Books
Already have a book you want to read? Import any DRM-free EPUB from your device. Your personal library, your target language, all the same translation and vocabulary tools.
Vocabulary Tracking
Every word you look up is saved automatically. Color-code your vocabulary, review with flashcards, and watch your comprehension grow over time.
Full-Page Translation
See the original text and the English translation side by side. Horizontal or vertical split — your choice. Adjust the ratio to match your comfort level.
Text-to-Speech
Listen to any page read aloud in the target language. Adjustable speed — slow it down while you're learning, speed up as you improve.
Flashcard Review
Study the vocabulary you've saved with animated flip cards. Filter by book, date, or color tag. Review the words you actually encountered while reading.
How It Works
Start reading in a new language in under a minute.
Pick a book in your target language
Browse or search Project Gutenberg's library by language. Thousands of titles in Spanish, French, German, Japanese, and more — all free, all real literature. Or import your own DRM-free EPUB if you already have a book in mind.
Read with live translation beside you
The original text and English translation sit side by side. Tap any word you don't know for an instant translation. No app-switching, no broken flow.
Build your vocabulary naturally
Every word you look up is saved automatically. Review with flashcards, track your progress, and watch the number of lookups drop as you read more. That's real learning.
Languages
11 languages. Thousands of books each.
Pricing
No ads. No subscription. Ever.
The free tier has everything you need to start learning. Premium removes all daily limits with a single $6.99 purchase — available now on Google Play, no recurring charges, ever.
On a previous version with a promo code? Your Premium status carries over — nothing to do.
Free
$0
- ✓Full Project Gutenberg library
- ✓30 word translations per day
- ✓30 saved vocabulary words
- ✓Full-page translation
- ✓Flashcard review
- ✓3 text-to-speech reads per day
Premium
$6.99
- ✓Everything in Free
- ✓Unlimited word translations
- ✓Unlimited saved vocabulary
- ✓Unlimited text-to-speech
- ✓No daily limits — ever
- ✓Support an indie developer
Stay in the Loop
Get the Polyglot's Reading List — free.
50 of the best free books for learning Spanish, French, German, Italian, Portuguese, and more — curated by difficulty level with Gutenberg links. Subscribe to the Cadmus Lab newsletter and it's yours.
FAQ
Common questions
Is Decipher really free?
Yes. The free tier gives you the full Gutenberg library, 30 daily word translations, vocabulary flashcards, and full-page translation. No ads, no subscription. The optional premium upgrade ($6.99, one-time) removes all daily limits.
What books are available?
Decipher connects to Project Gutenberg, a library of over 70,000 public-domain books. You'll find classics like Don Quijote, Le Petit Prince, Grimm's Fairy Tales, and thousands more across 11 languages. You can also import any DRM-free EPUB from your device — so if the book you want isn't on Gutenberg, you can still read it with all the same translation and vocabulary tools.
Do I need to be good at a language to use this?
No. The full-page translation shows you the meaning of everything on screen. Tap any word you don't know. Start with short, simple books and work your way up. The first few pages will be slow — that's normal and expected.
Is it available on iOS?
Decipher is currently available on Android via Google Play. iOS support is being explored for a future release.
Can I import my own books?
Yes. You can import any DRM-free EPUB file from your device. Tap-to-translate, vocabulary tracking, flashcards, full-page translation, and text-to-speech all work the same way with imported books as they do with Gutenberg titles.
Start reading in a new language today.
Free on Google Play. No account required. Pick a book and start reading in under a minute.
Download on Google PlayAndroid • Free • No ads • No subscription