Most flashcard apps teach vocabulary in a fixed order: JLPT level, textbook chapter, or someone's idea of what's "basic." Waffuru does it differently. Every card in our database has frequency rankings from four real-world sources, and your personal weights determine the order you encounter them.

The Four Frequency Sources

Each word, kanji, and kana card carries four frequency rankings, each representing how commonly it appears in a specific domain:

• Spoken: frequency in conversational Japanese, sourced from subtitles
• Written: frequency in newspapers, novels, and formal publications
• Web: frequency across Japanese websites, forums, and social media
• Anime: frequency in anime (hopefully with manga being added in the future)

How Your Weights Work

In your study settings, you set four weights that must sum to 100. A default balanced split might be 30/30/20/20, but if you're studying Japanese primarily to watch anime, you might set Anime to 60 and distribute the rest. If you're preparing for business, you'd lean into Written and Spoken.

When Waffuru builds your study session, it computes a weighted score for every unstudied card and feeds you the most frequent for your selections.

Dynamic, Not Static

This means two users with different goals will learn the same cards in completely different orders, each tuned for what they'll actually encounter.