jpdb.io
Tells you the difficulty and exact vocabulary of specific anime, games and novels.
WebsitesToolsFreeIntermediateAdvancedA2–C1
What it actually is
Its killer feature is per-media word lists: look up a specific show or novel, see how many words it uses and what percentage you already know, then pre-study that deck before you start. The built-in SRS is fast and keyboard-driven. It is free but rough around the edges — sparse documentation, an opinionated review algorithm, and a small one-person-project feel — and it assumes you have already got past the beginner stage.
What it covers
- Vocabulary
- Reading
- Immersion