A couple of single-file browser tools I built for language practice. No install, no server — just open and go. All progress lives in your browser's localStorage.

🎯 Quizzer

A spaced-repetition flashcard app in one HTML file. Drop in a CSV deck and study.

  • 🧠 FSRS-4.5 spaced repetition (tracks stability, difficulty, due dates per card)
  • 📥 Import decks as CSV via drag-and-drop
  • 🎛️ Study modes: spaced repetition, least practiced, random, browse
  • ⭐ Self-rate each answer: Again / Hard / Good / Easy
  • 📊 Session summaries, mastery charts, response-time breakdowns
  • 💾 Export / import full state as JSON
  • 🌍 Multi-language UI (EN, NL, IT)
Launch Quizzer →

🌍 Translator

AI-powered translation practice. Pick a language pair, translate sentences, get instant feedback with adaptive difficulty.

  • 🗣️ 8 languages, any direction (EN, NL, ES, TR, DE, IT, EL, FR)
  • 🤖 Claude evaluates each attempt: score, ideal translation, grammar notes
  • 📈 Adaptive difficulty — the AI adjusts based on your recent performance
  • 🏅 CEFR sub-levels (A1- through B2+) tracked over time
  • 🔁 Retry injection: periodically re-serves sentences you got wrong
  • ⚡ Speed bonus for fast correct answers (carrot, not stick)
  • 🔊 Optional TTS playback of expected translations (bring your own OpenAI key)
  • 🔑 Bring your own Anthropic API key — no server, no middleman
Launch Translator →