All Features

Everything You Need to Master English Vocabulary

One platform. Six practice modes. 640+ collections. AI-powered spaced repetition. Everything you need to build your English vocabulary — completely free.

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Practice Modes

6 Practice Modes

Each mode engages different parts of your brain for deeper, longer-lasting learning

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Flashcards

Classic flip cards with spaced repetition scheduling

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Multiple Choice

Test recognition with 4 options

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Fill in the Blanks

Type the word for active recall

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Matching

Match words to definitions

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Dictation

Listen and type

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Listen & Choose

Hear the word, pick meaning

Smart Learning

AI That Adapts to You

penguen.io's AI-powered spaced repetition tracks your performance on every word and schedules reviews at the perfect moment — just before you'd forget.

AI spaced repetition adapts to your performance
AI pronunciation for every word
Progress tracking with streaks, stats & heatmap

Learn about spaced repetition

How It Works

Traditional flashcard apps treat every word the same — showing them all at equal intervals, regardless of difficulty. This wastes time on words you already know.

penguen.io's algorithm monitors your accuracy and response time on every single word. Words you struggle with appear more frequently. Words you've mastered fade into the background. The result: faster learning with less study time.

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Content Library

640+ Curated Collections

Professionally curated vocabulary sets organized by level, topic, and exam. Not user-generated junk.

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By Level

From beginner basics to advanced academic vocabulary. Each collection is tagged with difficulty so you study at the right level.

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topic

By Topic

Travel, business, technology, health, food, culture, and dozens more. Learn vocabulary that's relevant to your life and interests.

Browse

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By Exam

IELTS, TOEFL, Cambridge, PTE, and more. Study the exact vocabulary that appears on your target exam.

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Motivation

Social & Motivation

Stay motivated with streaks, leaderboards, and achievements

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Global Leaderboards

Compete with learners worldwide. See where you rank and stay motivated to keep climbing.

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Daily Streaks

Build a study habit with daily streaks. Don't break the chain — consistency is the key to vocabulary mastery.

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Achievement Badges

Earn badges for milestones like mastering 100 words, maintaining a 7-day streak, or completing a collection.

Platforms

Available Everywhere

Study on any device — your progress syncs automatically

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Web App

Study in any modern browser — no download required

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iOS App

Native iPhone and iPad app with offline support

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Android App

Native Android app with offline support

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Offline Mode

Download collections and study without internet

Pricing

Completely Free

No ads. No hidden costs. No subscription. Just learning. penguen.io is free because we believe vocabulary learning should be accessible to everyone.

Learn why we're free

Frequently Asked Questions

Is penguen.io really free? expand_more

Yes, 100% free. No ads, no hidden costs, no subscription fees. All 6 practice modes, 640+ collections, spaced repetition, and offline mode are included at no charge.

What practice modes are available? expand_more

penguen.io offers 6 practice modes: Flashcards with spaced repetition, Multiple Choice, Fill in the Blanks, Matching, Dictation, and Listen & Choose. Each mode engages different parts of your brain for deeper learning.

Can I use penguen.io offline? expand_more

Yes! Download collections to your device and study anywhere without an internet connection. Your progress syncs automatically when you reconnect.

What languages are supported? expand_more

penguen.io supports translations in 11 languages: Spanish, Turkish, French, German, Italian, Japanese, Chinese, Portuguese, Russian, and Polish. Learn English vocabulary with meanings in your native language.

Start Learning Free

Join thousands of learners mastering English vocabulary with penguen.io. No credit card needed.

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