The smartest way to learn a language
SRS flashcards, audiobooks, music, video clips, and AI-powered word analysis — learn effectively in 15 languages.
Why Den?
Den removes the biggest obstacles to language learning through science-backed methods and modern technology.
Contextual Learning
Instead of memorizing words in isolation, learn them in real sentences and authentic media — songs, stories, and examples.
Forget-Proof Retention
Scientifically optimized review scheduling powered by the SM-2 algorithm. Review at exactly the right time for long-term memory.
Never Get Bored
5 distinct learning modes: flashcards, music, audiobooks, video clips, and search. Every day feels different.
Pronunciation Support
Hear correct pronunciation from two native-speaker voices (Ash & Coral) and learn to speak with confidence.
Idioms & Phrases
AI-powered contextual analysis that goes beyond dictionary definitions — understand idioms and set phrases the way native speakers use them.
Progress Tracking
Vocabulary growth, daily streaks, and accuracy metrics. Watch your progress in concrete numbers.
Powerful Features
Den covers every stage of the language learning journey with a rich set of tools.
Smart Flashcards (SRS)
Vocabulary learning powered by a scientific spaced-repetition algorithm
- ✓4 stages: New → Learning → Review → Known
- ✓Optimized review scheduling via the SM-2 algorithm
- ✓Audio pronunciation with 2 teacher voices (Ash & Coral)
- ✓Image-supported word cards
- ✓Personalized learning pace
Level Assessment System
Build your personalized learning program in 6 steps. Precise level detection across a 6,221-word corpus using a binary search algorithm.
Select Your Native Language
Choose your native language from 15 options
Select Your Target Language
Choose the language you want to learn
Choose Your Approach
Speaking, Writing, or Comprehensive
Set Your Daily Goal
Study plans ranging from 5 to 30 minutes per day
Take the Placement Test
40-question adaptive test to assess your level
Your Program Is Ready
Your personalized learning program awaits
Result Bands
15 Languages Supported
Learn from the world's most widely spoken languages.
Platform Integrations
Den stays with you everywhere on your phone. Seamless learning through system integrations.
iOS Share Extension
Look up any word by sharing text from any app
iOS Widget
Daily word suggestions right on your home screen
Push Notifications
Smart study reminders to keep you on track
Dark / Light Theme
Eye-friendly theme options, comfortable in any environment
Ready to learn a new language?
Explore a science-backed, content-rich learning experience across 15 languages — starting right now.
Supports iOS 13+ and Android 8+ • No credit card required