DuoCards - Vocabulary Builder

Contains adsIn-app purchases
57.5K 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.
Build vocabulary with AI flashcards and video lessons
Updated on
Aug 31, 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

55.5K reviews
T C
December 25, 2024
Helpful way to enrich one's vocabulary. A few issues: a loud sound comes out of the speaker sometimes when swiping cards; when words are saved from an AI-generated story or other material, the example sentence provided when studying the term later on is often incomplete and sometimes doesn't make sense; the pronunciation is incorrect in some cases. Regardless, a good hands-on complementary tool for language learning. Beware: wild email spam (1 per hour) but unsubscribing seems to have worked.
3 people found this review helpful
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DuoCards
January 5, 2025
Hi, for the cracking sound, could you email us at support@duocards.com with details, your device type, and OS version? :) Regarding incomplete example sentences, what language are you studying? We’ve never had complaints about this issue before. Michaela from DuoCards
Eine Kleine Spienne
June 16, 2024
I rate the flow efficient. The app is designed stylish. The only thing I couldn't find without searching for it is a dark theme. It's just that I don't like ads, why I have to abandon ship. Besides that, as a believer that commercials should be a program, which you can opt-in at your disgression-- without any restitution - I wouldn't mind buying modules in the application when prices are affordable. Ads, really don't sell me. Ads are a sign of an oppressed society. Oppressing is bad,mojo. XX
2 people found this review helpful
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DuoCards
July 16, 2024
Hello, ads help us keep our platform free and accessible for everyone. If you're up for an ad-free experience, we've got a cool subscription plan that not only removes ads but also adds many extra features. For dark mode, you can find it under the settings icon on each card. Michaela form DuoCards
Ayna Seddigh
July 21, 2022
Many languages as the native language option👌 (specifically persian), would be a lot better if the app could work completely on the target language; you could learn and practice English words based on English definition and synonyms (the translation would be hidden or sth). Moreover, it would be a lot better if we could see the definition or synonyms of the chosen word in the target language(English for example) while watching videos. Wish we could change the limit for adding words at one go.
5 people found this review helpful
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What’s new

Learn more wherever you are with reliable offline study and syncing. Create personalized card sets with AI, get detailed pronunciation feedback, and practice with richer roleplays and comprehension exercises. We also added language-level progress, mobile deck export, and easier set search—plus many fixes and performance improvements.