Asked as someone learning Japanese. Findings drawn from Japanese-specific research are framed for Japanese learners and may not hold for other languages; where the evidence is general second-language research, the report says so.
Yes — the research consistently supports flashcards, especially digital ones with spaced repetition, as an effective way to build vocabulary at the beginner stage, and beginners tend to benefit more from digital/app-based flashcards than more advanced learners do. However, flashcards work best as one tool among several: some studies found other methods (like games or general mobile-learning apps) can produce equal or even better vocabulary gains or engagement, and flashcards alone don't build speaking, listening, or handwriting skills. None of these studies tested English speakers learning Japanese directly, so specifics about kanji or kana aren't directly addressed — the closest evidence is a study of Japanese students learning English and a study on Chinese character recognition.
A study of 139 Japanese university students learning English vocabulary found that digital flashcards produced significantly bigger gains than paper flashcards specifically for students at lower proficiency levels, while advanced students did equally well with either format.6
In plain terms
When compared to other methods, flashcards sometimes come out ahead and sometimes behind, depending on what's measured. One study of beginner Chinese learners found a board game produced better final learning outcomes than flashcards, but flashcards produced higher motivation and more absorbing engagement. Another study found mobile learning apps beat flashcards for vocabulary gains, and a review of many studies suggests newer app-based tools that include spaced repetition and gamification tend to edge out plain flashcards over time.2,3,12
The core mechanism that makes flashcards effective is spaced repetition — reviewing words repeatedly over time rather than all at once — and this is the feature researchers say actually drives long-term retention, more than the flashcard format itself.1,5,9,13
In plain terms
Example
Flashcards that combine text with audio and a picture (multimodal cards) produced significantly fewer memory lapses than plain text-only flashcards, in a controlled study of learning new vocabulary.7
A long-term single-learner study of beginner Welsh vocabulary found that individual words often required far more repetitions to stick than the 5-12 typically cited in vocabulary research, and that certain word types (like adjectives) were much harder to learn than others (like nouns).9
In a survey of undergraduates learning Arabic, flashcards were the third most frequently chosen favorite learning strategy, behind interacting with a teacher and speaking practice, and ahead of pronunciation drills and grammar study.8
In a study of beginner Chinese learners, interactive whiteboard activities that used flashcard-like visual repetition were rated as helpful for recognizing characters, though the same students said these tools were less helpful for actually being able to write characters by hand or for improving speaking and listening.10
For a beginner learning Japanese, flashcards are a solid choice for building vocabulary, especially if you use a digital app with built-in spaced repetition (like Anki) rather than plain paper cards or cramming — this matters most while you're still a beginner, since research shows the gap between digital and paper cards narrows once you're more advanced. Where possible, choose or make cards that include audio and an image alongside the text, since multimodal cards have been shown to reduce forgetting compared to text-only cards. Since flashcards mainly build vocabulary recognition and recall, pair them with other activities — conversation practice, listening, and writing practice — to develop the skills flashcards don't cover, and don't be discouraged if some words (particularly ones without a physical form, like grammar particles or abstract terms) take far more repetitions to stick than others.