Polylingo vs BookLight
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Polylingo
Enhance language learning through reading with instant translations, synchronized audio narration, and AI-generated stories. Save new vocabulary and import your own content to practice reading in a foreign language.
- Instant tap-to-translate
- Audio narration with word highlighting
- AI-powered story generation
- Personal phrase book
- Import EPUB, PDF, and text files
- 10 supported languages
- Customizable reading themes
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Read in a foreign language — without the frustration. PolyLingo turns reading into your most powerful language learning tool. Tap any word for an instant translation. Listen to native-quality narration with every word highlighted as it's spoken. Save vocabulary to your personal phrase book. And when you run out of things to read, let AI write a story just for you. INSTANT TAP-TO-TRANSLATE Tap any word or select a phrase to see its meaning instantly. No copying, no switching apps. Translations include pronunciation (IPA), part of speech, and conjugation info — powered by offline dictionaries that work without Wi-Fi. AUDIO NARRATION WITH WORD HIGHLIGHTING Listen to stories read aloud with professional-quality audio. Every word highlights in sync as it's spoken, so you train your ears and eyes at the same time. Adjust playback speed from 0.5x to 2.0x. Perfect for commutes, workouts, or winding down. AI-POWERED STORIES AT YOUR LEVEL Choose your genre, difficulty level, and interests — PolyLingo generates a complete story tailored to you. Pick from narrative, conversational, descriptive, poetic, or simple writing styles. Every story matches your CEFR level (A1 to C1) so you're always in the sweet spot: challenged but never lost. YOUR PERSONAL PHRASE BOOK Save any word or phrase with one tap while reading. Every entry keeps its context, source, pronunciation, and translation. Review your vocabulary anytime and watch your word count grow day by day. CURATED LIBRARY + YOUR OWN BOOKS Browse stories organized by difficulty, genre, and language. Import your own EPUB, PDF, or text files. Filter by CEFR level (A1–C2) to find content that matches exactly where you are. 10 LANGUAGES SUPPORTED Learn English, Spanish, French, German, Italian, Portuguese, Japanese, Korean, Chinese, or Russian — from 6 home languages. DESIGNED FOR COMFORTABLE READING Choose between Dark, Light, and Sepia themes. Adjust font size. Read in immersive fullscreen mode. Your reading position and audio progress are always saved — pick up right where you left off. POLYLINGO PRO Unlock unlimited AI story generation, advanced phrase book features, and cross-device sync with a free 3-day trial. Whether you're a beginner sounding out your first sentences or an advanced learner tackling literature, PolyLingo meets you where you are — and makes every page count. Download now and start reading in your target language today. This app uses Apple's EULA: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
BookLight
This app helps language learners build vocabulary by translating words with a single tap while reading EPUB, PDF, or TXT files. It automatically saves new words and uses spaced repetition flashcards to aid memorization, eliminating the need for manual flashcard creation or app switching.
- Tap to translate words instantly
- Automatic vocabulary saving
- Spaced-repetition flashcards
- Import EPUB, PDF, TXT files
- Offline reading support
- Customizable reading themes and fonts
- Pronunciation audio
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Reading a book in another language? Stop breaking your flow to look words up. BookLight translates any word with a single tap — and remembers it for you. BookLight is a EPUB & PDF & Txt reader built for language learners. Tap a word for an instant translation, and it's saved to your vocabulary automatically. Then spaced-repetition flashcards bring it back right before you'd forget — so every reading session actually builds your vocabulary. No app-switching. No flashcards to make by hand. Perfect for language learners, foreign-book readers, and anyone studying for TOEFL or IELTS. Key Features: Start Reading in Seconds — Free Classics Inside - Download from various free classics (Project Gutenberg) right inside the app — no files to find, no setup. - Or import your own DRM-free EPUB & PDF & TXT files from your device. - Read offline anytime, with your reading progress saved and restored automatically. Tap to Translate — Without Losing Context - Tap any word for an instant translation: meaning by part of speech, phonetics, and an example sentence. - Tap an inflected word and see its base form, too. - Hear the pronunciation read aloud with one tap. - Every word you tap is saved automatically — together with the sentence and the book it came from. - Translate into 9 languages: Korean, Spanish, French, Japanese, Chinese, Russian, Hindi, Vietnamese, and Indonesian. Remember Every Word — Spaced Repetition - Your vocabulary list builds itself as you read — no manual entry. - Review with spaced-repetition (SRS) flashcards that resurface each word right before you forget it. - Tap any saved word to jump straight back to the exact spot in the book. - Keep a daily streak and a smart reminder nudges you only when words are actually waiting. Your Book Becomes an Audiobook — AI Read-Aloud - A natural, human-like on-device AI voice reads your book aloud — choose from 10 voices. - The sentence being read is highlighted, so you can follow along with your eyes and ears. - Playback keeps going with the screen off or while you use other apps. - Playback speed from 0.5x to 2x — faster on the commute, slower before sleep. - Speech is synthesized on your device, so it works without an internet connection. Read Your Way, Day or Night - 7 fonts and 25 reading themes — from Sepia and Night to Rose Quartz, Sage, and Midnight. - Adjust font size and line spacing until the page feels just right. - Choose how you read — page turns or continuous scroll. - Read hands-free with auto-scroll — 10 speed levels, and a single touch pauses instantly. - Full dark mode plus automatic system-theme sync. - Side-by-Side two-page display mode for comfortable reading on tablets. Loved by readers in 10+ countries. Supports 9 translation languages and works with any DRM-free EPUB or TXT file. Download BookLight today — and turn every reading session into a vocabulary lesson! - Privacy Policy: https://pearlismylove.github.io/apps/book-light/privacy-policy.html - Terms And Conditions: https://pearlismylove.github.io/apps/book-light/terms-and-conditions.html - Support: https://pearlismylove.github.io/apps/book-light/support.html
Screenshots
Verdict
The clearest difference is iOS requirement: Polylingo at 13.0 against BookLight's 16.4. On price, update cadence, ads and in-app purchases there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. Polylingo sells 3 in-app purchases, starting at $5.99 per 7 days and BookLight sells 3 in-app purchases, starting at $0.99 per month. Whichever you choose, the download price is not the number that matters.
Polylingo ships an update every 6 days, BookLight every 5 days. The most recent releases landed on September 29, 2026 and October 5, 2026 respectively.
| Parameter | Polylingo | BookLight |
|---|---|---|
| Price | Free | Free |
| Rating | 4.8 (4 ratings) — better | — |
| Positive reviews | — | 100.0% of reviews |
| Number of ratings | 4 — better | — |
| Update frequency | Every 6 days | Every 5 days — better |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | Freemium | Free with in-app purchases |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 13.0 — better | 16.4 |
| Further details — not scored | ||
| Size | 128 MB | 94 MB |
| Age rating | 9+ | 4+ |
| Developer | Jesse Deng | Jungjun Lee |
Customer experience
Polylingo
BookLight
In-app purchases
Polylingo
- Weekly Pro Subscription$5.997 Days
- Monthly Pro$14.991 Month
- Yearly Pro Subscription$39.991 Year
BookLight
- Monthly Plan$0.991 Month
- Yearly Plan7 Days trial$7.991 Year
- Lifetime Plan$9.99









