10 Best Duolingo Alternatives & Competitors (2026)

Anki is the most widely used cross-platform spaced repetition system built on the same SM-2 algorithm that powers CleverDeck. It offers completely free desktop and Android apps plus a paid iOS app, massive user-shared language decks, and powerful add-ons. Unlike CleverDeck's curated 3000-word sets, Anki relies on community content and requires more initial setup, but it works on every device and has no subscription cost for core use.

Memrise combines user-generated and official language courses with spaced repetition and mnemonic techniques. Available on iOS and Android, it offers both free and Pro tiers. Compared with CleverDeck it provides broader course variety and community content but less emphasis on polished 3000-word core vocabulary decks with consistent native audio.

Quizlet is a popular flashcard platform with millions of user-created sets and built-in spaced repetition modes. It works on web and mobile with generous free features plus Quizlet Plus. While it lacks CleverDeck's hand-crafted language decks and professional audio, its large library and study modes make it a frequent choice for students seeking free or low-cost alternatives.

SuperMemo pioneered the SM-2 algorithm and offers advanced scheduling on Windows with mobile companions. It is paid software aimed at power users. Unlike CleverDeck's simple iOS focus and ready language content, SuperMemo provides deeper customization at the cost of a steeper learning curve and limited mobile polish.

Drops uses visual spaced repetition for vocabulary with beautiful illustrations and short daily sessions. Available on iOS and Android via subscription, it targets the same language learners as CleverDeck but emphasizes visual memory over example sentences and audio. It is more limited in depth for serious intermediate study.

Babbel offers subscription-based language courses that incorporate spaced repetition alongside dialogues and speaking practice. It provides more structured lessons than CleverDeck's flashcard focus but at a higher monthly price. Users switching from CleverDeck often cite the conversational elements as the main trade-off for losing simple vocabulary decks.

LingQ combines imported content, spaced repetition, and extensive reading/listening libraries for language acquisition. It is subscription-based and works across platforms. Compared with CleverDeck it shifts emphasis from curated flashcards to consuming real-world material, suiting users who want context beyond isolated vocabulary.

Rosetta Stone is a premium immersive language program with visual association and speech recognition. It uses some spaced repetition but focuses on full lessons rather than standalone decks. Priced higher than CleverDeck, it appeals to learners wanting structured courses instead of flexible flashcard review.

RemNote merges note-taking with spaced repetition and knowledge management. Free for core use with optional paid tiers, it runs on web and desktop. It offers more flexibility than CleverDeck for building personal knowledge bases but requires users to create or import their own language content rather than using pre-made decks.