, in Japanese.
Learn and retain the words you explore through deep dives into the most fascinating culture on Earth.


  • Stay immersed. Kotobaten is a flashcards app built for immersion learners that want to capture and learn vocabulary they discover themselves. There are no pre-built lists here.
  • Stay focused. Kotobaten is minimum you need to build your word collection, learn it, and retain it. No distracting features that derail you or give you false sense of progress.
  • Stay consistent. Vocabulary building is all about consistency. Our spaced repetition algorithm balances learning the new and refreshing the old.
👋 I'm Jan, a long-time Japanese learner, and Kotobaten is my side project.

Some people magically remember words after hearing them twice.
I'm not one of them 😅.

Over the last two years, Kotobaten has helped me learn around a thousand words per year. Hopefully you can find it helpful too! ー Jan