DuoCards - Vocabulary Builder

Contains adsIn-app purchases
4.6
52.6K reviews
Content rating
PEGI 3
5M+
Downloads
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About this app

Build vocabulary and learn languages with DuoCards, a flexible vocabulary builder for English and 50+ languages. Save new words from videos, articles, subtitles, courses, then practice with AI flashcards, speaking exercises, listening practice, and spaced repetition so the words stay in memory.

DuoCards is built for learners who want more than generic language lessons. You can discover useful words in real content, save them into a personal vocabulary deck, and review them with smart language flashcards that adapt to your progress.

What you can do with DuoCards:

- Build English vocabulary with flashcards that repeat at the right time
- Learn words from videos, subtitles, articles, courses, and shared decks
- Practice conversations with an AI language tutor for daily situations
- Improve pronunciation with speaking and listening exercises
- Save phrases, example sentences, and translations in one vocabulary app
- Study Spanish, French, German, Japanese, Korean, Italian, Portuguese, Russian, and more
- Create private decks or learn from public vocabulary sets made by other learners
- Use offline learning when you want to review without a stable connection

Learn from videos and articles

Language learning works better when words appear in context. DuoCards lets you save vocabulary from videos with subtitles and from foreign language articles, so you can connect each word with a real sentence, topic, and memory. Tap a word, check the translation, save it to your deck, and review it later.

Practice with AI flashcards

DuoCards combines classic flashcards with AI practice. Review words, listen to pronunciation, speak your answers, ask for examples, and practice short conversations. Use the AI tutor to understand grammar, see words in context, and turn your saved vocabulary into useful phrases.

A vocabulary builder for many goals

Use DuoCards as an English vocabulary app, a Spanish flashcards app, a language flashcards app, or a daily vocabulary builder for school, travel, work, exams, and everyday conversations. You can learn beginner words, advanced phrases, useful verbs, pronunciation, listening, and sentence patterns.

How DuoCards works:

1. Choose the language you want to learn.
2. Find useful words in videos, articles, courses, decks, or your own notes.
3. Save words and phrases to your personal vocabulary deck.
4. Practice with flashcards, AI conversations, pronunciation, and listening.
5. Review with spaced repetition until the words become familiar.

Why learners use DuoCards:

- Real content: learn from videos, articles, and examples instead of isolated word lists
- Smart review: spaced repetition helps you remember vocabulary for longer
- AI practice: turn saved words into conversations, stories, and grammar examples
- Flexible decks: create your own word lists or study public language sets
- Many languages: learn English and 50+ languages from one app
- Clear progress: see which words are new, known, or ready to review
- Offline review: keep practicing vocabulary while traveling or commuting

DuoCards is useful if you are learning English, improving Spanish vocabulary, studying French words, reviewing German phrases, practicing Japanese or Korean, or building a personal word bank in another language. It works for beginners who need simple vocabulary and for advanced learners who want to remember words from real content.

Use DuoCards for:

- English vocabulary and pronunciation practice
- Spanish, French, German, Italian, Portuguese, Russian, Japanese, and Korean words
- Language flashcards with spaced repetition
- AI tutor practice for speaking and grammar
- Video lessons, subtitles, and article-based learning
- Personal word lists, shared decks, and ready-made courses
- Daily review sessions for school, travel, work, or conversation

Download DuoCards and build vocabulary from real content. Learn languages with AI flashcards, video lessons, articles, speaking practice, listening exercises every day.
Updated on
Jan 21, 2026

Data safety

Safety starts with understanding how developers collect and share your data. Data privacy and security practices may vary based on your use, region, and age. The developer provided this information and may update it over time.
This app may share these data types with third parties
App activity
This app may collect these data types
Personal info, Financial info and 3 others
Data is encrypted in transit
You can request that data be deleted

Ratings and reviews

4.6
50.8K reviews
Tobias Bayer
November 30, 2023
I just wanted a simple vocabulary trainer with predefined cards and found it here! One drawback is the card quality, at least for spanish from english. They are often written in different styles like with or without "to/the" so you don't know if it is asking for a verb or noun. And some cards are pretty weird or simply wrong/nonsense.
6 people found this review helpful
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Ryuichiro Suzuki
April 14, 2023
A subscribe worthy app. All I wish for is a more offline availability. Sometimes, I wanna do it on the train where sometimes cellular can't reach, or on planes. Yet, I love the recent feature of AI assisted explanations. It'd be nice if I don't have to open a modal. I kinda wanna see it all the time if possible. Also, can you add the translation of the example sentences generated by AI in the new AI explanation modal?
4 people found this review helpful
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Kevin Shaffer
April 1, 2026
I wish you would spend less time with annoying floating elephants and fix your atrocious pronunciations.
65 people found this review helpful
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DuoCards
April 3, 2026
Hi Kevin, it was just our little April Fools’ prank, now it’s already gone. :)

What’s new

AI Roleplay - Practice real-world conversations in simulated scenarios
AI Stories - Interactive stories with comprehension exercises
Bookmarks - Save your current progress in an article for later
Transliteration - Read Chinese, Arabic, Japanese scripts easily
Auto Dark Mode - Study comfortably day or night
Smarter Translations - Context-aware translations
AI Grammar Feedback - Accurate corrections with explanations